From 585bb022a3f82ab77e1322bba50c1f5ef6e9ea26 Mon Sep 17 00:00:00 2001
From: tsteven4 <13596209+tsteven4@users.noreply.github.com>
Date: Mon, 30 Oct 2023 11:52:35 -0600
Subject: [PATCH 01/11] use container for garmin_fs ilinks.

and leave memory management up to the copy on write container.
---
 garmin.cc     |  2 +-
 garmin_fs.cc  | 42 +-----------------------------------------
 garmin_fs.h   | 28 ++++++++++++----------------
 garmin_gpi.cc |  4 ++--
 garmin_txt.cc |  4 ++--
 gdb.cc        | 47 ++++++++++++++++-------------------------------
 gpx.cc        | 26 ++++++++++++++------------
 random.cc     |  4 ++--
 unicsv.cc     |  4 ++--
 waypt.cc      | 18 ++++++++----------
 xcsv.cc       |  4 ++--
 11 files changed, 62 insertions(+), 121 deletions(-)

diff --git a/garmin.cc b/garmin.cc
index 1382f9ead..aafa3b209 100644
--- a/garmin.cc
+++ b/garmin.cc
@@ -1241,7 +1241,7 @@ d103_icon_number_from_symbol(const QString& s)
 static void
 garmin_fs_garmin_after_read(const GPS_PWay way, Waypoint* wpt, const int protoid)
 {
-  garmin_fs_t* gmsd = garmin_fs_alloc(protoid);
+  auto* gmsd = new garmin_fs_t(protoid);
   wpt->fs.FsChainAdd(gmsd);
 
   /* nothing happens until gmsd is allocated some lines above */
diff --git a/garmin_fs.cc b/garmin_fs.cc
index 148db9169..46a857d36 100644
--- a/garmin_fs.cc
+++ b/garmin_fs.cc
@@ -31,46 +31,6 @@
 
 #define MYNAME "garmin_fs"
 
-garmin_fs_t*
-garmin_fs_alloc(const int protocol)
-{
-  auto* result = new garmin_fs_t;
-
-  result->protocol = protocol;
-
-  return result;
-}
-
-garmin_fs_t* garmin_fs_t::clone() const
-{
-  auto* copy = new garmin_fs_t(*this);
-
-  /* do not deep copy interlinks, only increment the reference counter */
-  if (ilinks != nullptr) {
-    ilinks->ref_count++;
-  }
-
-#ifdef GMSD_EXPERIMENTAL
-  memcopy(subclass, other.subclass, sizeof(subclass));
-#endif
-
-  return copy;
-}
-
-garmin_fs_t::~garmin_fs_t()
-{
-  garmin_ilink_t* links;
-  if ((links = ilinks) != nullptr) {
-    links->ref_count--;
-    if (links->ref_count <= 0) {
-      while (links != nullptr) {
-        garmin_ilink_t* tmp = links;
-        links = links->next;
-        xfree(tmp);
-      }
-    }
-  }
-}
 
 bool
 garmin_fs_convert_category(const QString& category_name, uint16_t* category)
@@ -112,7 +72,7 @@ garmin_fs_merge_category(const QString& category_name, Waypoint* waypt)
   cat = cat | (garmin_fs_t::get_category(gmsd, 0));
 
   if (gmsd == nullptr) {
-    gmsd = garmin_fs_alloc(-1);
+    gmsd = new garmin_fs_t(-1);
     waypt->fs.FsChainAdd(gmsd);
   }
   garmin_fs_t::set_category(gmsd, cat);
diff --git a/garmin_fs.h b/garmin_fs.h
index 0535d85ac..20c68ccff 100644
--- a/garmin_fs.h
+++ b/garmin_fs.h
@@ -26,6 +26,7 @@
 
 #include <cstdint>     // for int32_t, int16_t, uint16_t
 
+#include <QList>       // for QList
 #include <QString>     // for QString
 
 #include "defs.h"
@@ -41,9 +42,9 @@
 */
 
 struct garmin_ilink_t {
-  int ref_count;
-  double lat, lon, alt;
-  garmin_ilink_t* next;
+  double lat;
+  double lon;
+  double alt;
 };
 
 struct garmin_fs_flags_t {
@@ -117,22 +118,21 @@ class garmin_fs_t : public FormatSpecificData {
   QString email;				/* email address */
   unsigned int duration; /* expected travel time to next route point, in seconds, only when auto-routed */
 
-  garmin_ilink_t* ilinks{nullptr};
+  QList<garmin_ilink_t> ilinks;
 #ifdef GMSD_EXPERIMENTAL
   char subclass[22]{};
 #endif
 
 public:
   garmin_fs_t() : FormatSpecificData(kFsGmsd) {}
-private:
-  garmin_fs_t(const garmin_fs_t& other) = default;
-public:
-  garmin_fs_t& operator=(const garmin_fs_t& rhs) = delete; /* not implemented */
-  garmin_fs_t(garmin_fs_t&&) = delete; /* not implemented */
-  garmin_fs_t& operator=(garmin_fs_t&&) = delete; /* not implemented */
-  ~garmin_fs_t() override;
+  explicit garmin_fs_t(int p) : garmin_fs_t() {protocol = p;}
+
+
+  garmin_fs_t* clone() const override
+  {
+    return new garmin_fs_t(*this);
+  }
 
-  garmin_fs_t* clone() const override;
   static garmin_fs_t* find(const Waypoint* wpt) {
     return reinterpret_cast<garmin_fs_t*>(wpt->fs.FsChainFind(kFsGmsd));
   }
@@ -214,10 +214,6 @@ class garmin_fs_t : public FormatSpecificData {
 #undef GEN_GMSD_STR_METHODS
 };
 
-garmin_fs_t* garmin_fs_alloc(int protocol);
-void garmin_fs_destroy(void* fs);
-void garmin_fs_copy(void** dest, const void* src);
-
 /* ..convert_category: returns true=OK; false=Unable to convert category */
 bool garmin_fs_convert_category(const QString& category_name, uint16_t* category);
 
diff --git a/garmin_gpi.cc b/garmin_gpi.cc
index 340c823be..efccc3a3d 100644
--- a/garmin_gpi.cc
+++ b/garmin_gpi.cc
@@ -41,7 +41,7 @@
 
 #include "defs.h"
 #include "formspec.h"              // for FormatSpecificDataList
-#include "garmin_fs.h"             // for garmin_fs_t, garmin_fs_alloc
+#include "garmin_fs.h"             // for garmin_fs_t
 #include "gbfile.h"                // for gbfputint32, gbfgetint32, gbfgetint16, gbfputint16, gbfgetc, gbfputc, gbfread, gbftell, gbfwrite, gbfseek, gbfclose, gbfopen_le, gbfgetuint16, gbsize_t, gbfile
 #include "jeeps/gpsmath.h"         // for GPS_Math_Deg_To_Semi, GPS_Math_Semi_To_Deg
 
@@ -76,7 +76,7 @@ GarminGPIFormat::gpi_gmsd_init(Waypoint* wpt)
   }
   garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
   if (gmsd == nullptr) {
-    gmsd = garmin_fs_alloc(-1);
+    gmsd = new garmin_fs_t(-1);
     wpt->fs.FsChainAdd(gmsd);
   }
   return gmsd;
diff --git a/garmin_txt.cc b/garmin_txt.cc
index c49569445..3dd66e252 100644
--- a/garmin_txt.cc
+++ b/garmin_txt.cc
@@ -49,7 +49,7 @@
 
 #include "csv_util.h"              // for csv_linesplit
 #include "formspec.h"              // for FormatSpecificDataList
-#include "garmin_fs.h"             // for garmin_fs_t, garmin_fs_alloc, garmin_fs_convert_category, GMSD_SECTION_CATEGORIES
+#include "garmin_fs.h"             // for garmin_fs_t, garmin_fs_convert_category, GMSD_SECTION_CATEGORIES
 #include "garmin_tables.h"         // for gt_display_modes_e, gt_find_desc_from_icon_number, gt_find_icon_number_from_desc, gt_get_mps_grid_longname, gt_lookup_datum_index, gt_lookup_grid_type, GDB, gt_get_icao_cc, gt_get_icao_country, gt_get_mps_datum_name, gt_waypt_class_names, GT_DISPLAY_MODE...
 #include "inifile.h"               // for inifile_readstr
 #include "jeeps/gpsmath.h"         // for GPS_Math_Known_Datum_To_UTM_EN, GPS_Math_WGS84_To_Known_Datum_M, GPS_Math_WGS84_To_Swiss_EN, GPS_Math_WGS84_To_UKOSMap_M
@@ -1102,7 +1102,7 @@ parse_waypoint(const QStringList& lineparts)
   bind_fields(waypt_header);
 
   auto* wpt = new Waypoint;
-  garmin_fs_t* gmsd = garmin_fs_alloc(-1);
+  auto* gmsd = new garmin_fs_t(-1);
   wpt->fs.FsChainAdd(gmsd);
 
   for (const auto& str : lineparts) {
diff --git a/gdb.cc b/gdb.cc
index 5efbb55f3..c9c83f200 100644
--- a/gdb.cc
+++ b/gdb.cc
@@ -42,7 +42,7 @@
 
 #include "defs.h"                   // for Waypoint, warning, route_head, fatal, UrlLink, bounds, UrlList, unknown_alt, xfree, waypt_add_to_bounds, waypt_init_bounds, xstrtoi, route_add_wpt, route_disp_all, waypt_bounds_valid, xmalloc, gb_color, WaypointList, find_wa...
 #include "formspec.h"               // for FormatSpecificDataList
-#include "garmin_fs.h"              // for garmin_fs_t, garmin_ilink_t, garmin_fs_alloc
+#include "garmin_fs.h"              // for garmin_fs_t, garmin_ilink_t
 #include "garmin_tables.h"          // for gt_waypt_class_map_point, gt_color_index_by_rgb, gt_color_value, gt_waypt_classes_e, gt_find_desc_from_icon_number, gt_find_icon_number_from_desc, gt_gdb_display_mode_symbol, gt_get_icao_country, gt_waypt_class_user_waypoint, GDB, gt_display_mode_symbol
 #include "gbfile.h"                 // for gbfgetint32, gbfputint32, gbfgetc, gbfread, gbfwrite, gbfgetdbl, gbfputc, gbfgetcstr, gbfclose, gbfgetnativecstr, gbfopen_le, gbfputint16, gbfile, gbfcopyfrom, gbfputcstr, gbfrewind, gbfseek, gbftell, gbfgetcstr_old, gbfgetint16, gbfgetuint32, gbfputdbl
 #include "grtcirc.h"                // for RAD, gcdist, radtometers
@@ -440,7 +440,7 @@ GdbFormat::read_waypoint(gt_waypt_classes_e* waypt_class_out)
   waypt_ct++;
   res = new Waypoint;
 
-  gmsd = garmin_fs_alloc(-1);
+  gmsd = new garmin_fs_t(-1);
   res->fs.FsChainAdd(gmsd);
   res->shortname = fread_cstr();
   wpt_class = (gt_waypt_classes_e) FREAD_i32;
@@ -738,46 +738,37 @@ GdbFormat::read_route()
     }
 
     int links = FREAD_i32;
-    garmin_ilink_t* il_anchor = nullptr;
-    garmin_ilink_t* il_root = nullptr;
+    QList<garmin_ilink_t> il_list;
 #if GDB_DEBUG
     DBG(GDB_DBG_RTE, links)
     printf(MYNAME "-rte_pt \"%s\" (%d): %d interlink step(s)\n",
            qPrintable(wpt->shortname), wpt_class, links);
 #endif
     for (int j = 0; j < links; j++) {
-      auto* il_step = (garmin_ilink_t*) xmalloc(sizeof(garmin_ilink_t));
+      garmin_ilink_t il_step;
 
-      il_step->ref_count = 1;
-
-      il_step->lat = FREAD_LATLON;
-      il_step->lon = FREAD_LATLON;
+      il_step.lat = FREAD_LATLON;
+      il_step.lon = FREAD_LATLON;
       if (FREAD_C == 1) {
-        il_step->alt = FREAD_DBL;
+        il_step.alt = FREAD_DBL;
       } else {
-        il_step->alt = unknown_alt;
+        il_step.alt = unknown_alt;
       }
 
       if (j == 0) {
-        wpt->latitude = il_step->lat;
-        wpt->longitude = il_step->lon;
-        wpt->altitude = il_step->alt;
+        wpt->latitude = il_step.lat;
+        wpt->longitude = il_step.lon;
+        wpt->altitude = il_step.alt;
       }
 
-      il_step->next = nullptr;
-      if (il_anchor == nullptr) {
-        il_root = il_step;
-      } else {
-        il_anchor->next = il_step;
-      }
-      il_anchor = il_step;
+      il_list.append(il_step);
 
 #if GDB_DEBUG
       DBG(GDB_DBG_RTEe, true) {
         printf(MYNAME "-rte_il \"%s\" (%d of %d): %c%0.6f %c%0.6f\n",
                qPrintable(wpt->shortname), j + 1, links,
-               il_step->lat < 0 ? 'S' : 'N', il_step->lat,
-               il_step->lon < 0 ? 'W' : 'E', il_step->lon);
+               il_step.lat < 0 ? 'S' : 'N', il_step.lat,
+               il_step.lon < 0 ? 'W' : 'E', il_step.lon);
       }
 #endif
     }
@@ -832,19 +823,13 @@ GdbFormat::read_route()
     if (wpt != nullptr) {
       garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
       if (gmsd == nullptr) {
-        gmsd = garmin_fs_alloc(-1);
+        gmsd = new garmin_fs_t(-1);
         wpt->fs.FsChainAdd(gmsd);
       }
       garmin_fs_t::set_wpt_class(gmsd, wpt_class);
-      gmsd->ilinks = il_root;
-      il_root = nullptr;
+      gmsd->ilinks = il_list;
     }
 
-    while (il_root) {
-      garmin_ilink_t* il = il_root;
-      il_root = il_root->next;
-      xfree(il);
-    }
   } /* ENDFOR: for (i = 0; i < points; i++) */
 
   /* VERSION DEPENDENT CODE */
diff --git a/gpx.cc b/gpx.cc
index de176e454..787b68131 100644
--- a/gpx.cc
+++ b/gpx.cc
@@ -47,7 +47,7 @@
 #include <QtGlobal>                         // for qAsConst, QAddConst<>::Type
 
 #include "defs.h"
-#include "garmin_fs.h"                      // for garmin_fs_t, garmin_ilink_t, garmin_fs_alloc, garmin_fs_merge_category
+#include "garmin_fs.h"                      // for garmin_fs_t, garmin_ilink_t, garmin_fs_merge_category
 #include "garmin_tables.h"                  // for gt_color_index_by_rgb, gt_color_name, gt_color_value_by_name
 #include "geocache.h"                       // for Geocache, Geocache::UtfSt...
 #include "mkshort.h"                        // for MakeShort
@@ -218,7 +218,7 @@ GpxFormat::tag_garmin_fs(tag_type tag, const QString& text, Waypoint* waypt)
 {
   garmin_fs_t* gmsd = garmin_fs_t::find(waypt);
   if (gmsd == nullptr) {
-    gmsd = garmin_fs_alloc(-1);
+    gmsd = new garmin_fs_t(-1);
     waypt->fs.FsChainAdd(gmsd);
   }
 
@@ -1346,7 +1346,7 @@ GpxFormat::gpx_write_common_extensions(const Waypoint* waypointp, const gpx_poin
     // Although not required by the schema we assume that gpxx:RoutePointExtension must be a child of gpx:rtept.
     // Although not required by the schema we assume that gpxx:TrackPointExtension must be a child of gpx:trkpt.
     // Although not required by the schema we assume that gpxtpx:TrackPointExtension must be a child of gpx:trkpt.
-    garmin_fs_t* gmsd = garmin_fs_t::find(waypointp);
+    const garmin_fs_t* gmsd = garmin_fs_t::find(waypointp);
     switch (point_type) {
     case gpxpt_waypoint:
       writer->stackOptionalStartElement(QStringLiteral("gpxx:WaypointExtension"));
@@ -1401,19 +1401,21 @@ GpxFormat::gpx_write_common_extensions(const Waypoint* waypointp, const gpx_poin
       writer->stackEndElement(); // gpxx:WaypointExtension
       break;
     case gpxpt_route:
-      if (gmsd != nullptr && gmsd->ilinks != nullptr) {
+      if (gmsd != nullptr && !gmsd->ilinks.isEmpty()) {
         writer->stackOptionalStartElement(QStringLiteral("gpxx:RoutePointExtension"));
-        garmin_ilink_t* link = gmsd->ilinks;
-        garmin_ilink_t* prior = nullptr; // GDB files sometime contain repeated point; omit them
-        while (link != nullptr) {
-          if (prior == nullptr || prior->lat != link->lat || prior->lon != link->lon) {
+        double prior_lat; // GDB files sometime contain repeated point; omit them
+        double prior_lon;
+        bool first = true;
+        for (const auto& link : gmsd->ilinks) {
+          if (first || (prior_lat != link.lat) || (prior_lon != link.lon)) {
             writer->stackStartElement(QStringLiteral("gpxx:rpt"));
-            writer->stackAttribute(QStringLiteral("lat"), toString(link->lat));
-            writer->stackAttribute(QStringLiteral("lon"), toString(link->lon));
+            writer->stackAttribute(QStringLiteral("lat"), toString(link.lat));
+            writer->stackAttribute(QStringLiteral("lon"), toString(link.lon));
             writer->stackEndElement(); // "gpxx:rpt"
+            prior_lat = link.lat;
+            prior_lon = link.lon;
+            first = false;
           }
-          prior = link;
-          link = link->next;
         }
         writer->stackEndElement(); // gpxx:RoutePointExtension
       }
diff --git a/random.cc b/random.cc
index 7026a9e53..339c04602 100644
--- a/random.cc
+++ b/random.cc
@@ -28,7 +28,7 @@
 #include "defs.h"
 #include "random.h"
 #include "formspec.h"           // for FormatSpecificDataList
-#include "garmin_fs.h"          // for garmin_fs_t, GMSD_SET, garmin_fs_flags_t, garmin_fs_alloc
+#include "garmin_fs.h"          // for garmin_fs_t, GMSD_SET, garmin_fs_flags_t
 #include "src/core/datetime.h"  // for DateTime
 
 
@@ -104,7 +104,7 @@ Waypoint*
 RandomFormat::random_generate_wpt(int i, const QDateTime& time, const Waypoint* prev)
 {
   auto* wpt = new Waypoint;
-  garmin_fs_t* gmsd = garmin_fs_alloc(-1);
+  auto* gmsd = new garmin_fs_t(-1);
   wpt->fs.FsChainAdd(gmsd);
 
   do {
diff --git a/unicsv.cc b/unicsv.cc
index 92ca85043..48c483213 100644
--- a/unicsv.cc
+++ b/unicsv.cc
@@ -42,7 +42,7 @@
 #include "defs.h"
 #include "csv_util.h"              // for csv_linesplit, human_to_dec
 #include "formspec.h"              // for FormatSpecificDataList
-#include "garmin_fs.h"             // for garmin_fs_flags_t, garmin_fs_t, GMSD_GET, GMSD_HAS, GMSD_SETQSTR, GMSD_FIND, garmin_fs_alloc
+#include "garmin_fs.h"             // for garmin_fs_t
 #include "garmin_tables.h"         // for gt_lookup_datum_index, gt_get_mps_grid_longname, gt_lookup_grid_type
 #include "geocache.h"              // for Geocache, Geocache::status_t, Geoc...
 #include "jeeps/gpsmath.h"         // for GPS_Math_UKOSMap_To_WGS84_M, GPS_Math_EN_To_UKOSNG_Map, GPS_Math_Known_Datum_To_UTM_EN, GPS_Math_Known_Datum_To_WGS84_M, GPS_Math_Swiss_EN_To_WGS84, GPS_Math_UTM_EN_To_Known_Datum, GPS_Math_WGS84_To_Known_Datum_M, GPS_Math_WGS84_To_Swiss_EN, GPS_Math_WGS...
@@ -823,7 +823,7 @@ UnicsvFormat::unicsv_parse_one_line(const QString& ibuf)
     case fld_garmin_facility:
       gmsd = garmin_fs_t::find(wpt);
       if (! gmsd) {
-        gmsd = garmin_fs_alloc(-1);
+        gmsd = new garmin_fs_t(-1);
         wpt->fs.FsChainAdd(gmsd);
       }
       switch (unicsv_fields_tab[column]) {
diff --git a/waypt.cc b/waypt.cc
index 8130add75..77a219faa 100644
--- a/waypt.cc
+++ b/waypt.cc
@@ -230,22 +230,20 @@ double
 waypt_distance_ex(const Waypoint* A, const Waypoint* B)
 {
   double res = 0;
-  garmin_fs_t* gmsd;
 
   if ((A == nullptr) || (B == nullptr)) {
     return 0;
   }
 
-  if ((gmsd = garmin_fs_t::find(A)) && (gmsd->ilinks != nullptr)) {
-    garmin_ilink_t* link = gmsd->ilinks;
-
-    res = gcgeodist(A->latitude, A->longitude, link->lat, link->lon);
-    while (link->next != nullptr) {
-      garmin_ilink_t* prev = link;
-      link = link->next;
-      res += gcgeodist(prev->lat, prev->lon, link->lat, link->lon);
+  if (const garmin_fs_t* gmsd = garmin_fs_t::find(A); (gmsd != nullptr) && (!gmsd->ilinks.isEmpty())) {
+    auto prev_lat = A->latitude;
+    auto prev_lon = A->longitude;
+    for (const auto& link : gmsd->ilinks) {
+      res += gcgeodist(prev_lat, prev_lon, link.lat, link.lon);
+      prev_lat = link.lat;
+      prev_lon = link.lon;
     }
-    res += gcgeodist(link->lat, link->lon, B->latitude, B->longitude);
+    res += gcgeodist(gmsd->ilinks.last().lat, gmsd->ilinks.last().lon, B->latitude, B->longitude);
   } else {
     res = gcgeodist(A->latitude, A->longitude, B->latitude, B->longitude);
   }
diff --git a/xcsv.cc b/xcsv.cc
index d2c57e549..4a18e224f 100644
--- a/xcsv.cc
+++ b/xcsv.cc
@@ -51,7 +51,7 @@
 #include "defs.h"
 #include "csv_util.h"              // for csv_stringtrim, dec_to_human, csv_stringclean, human_to_dec, ddmmdir_to_degrees, dec_to_intdeg, decdir_to_dec, intdeg_to_dec, csv_linesplit
 #include "formspec.h"              // for FormatSpecificDataList
-#include "garmin_fs.h"             // for garmin_fs_t, garmin_fs_alloc
+#include "garmin_fs.h"             // for garmin_fs_t
 #include "geocache.h"              // for Geocache, Geocache::status_t, Geoc...
 #include "grtcirc.h"               // for RAD, gcdist, radtometers
 #include "jeeps/gpsmath.h"         // for GPS_Math_WGS84_To_UTM_EN, GPS_Lookup_Datum_Index, GPS_Math_Known_Datum_To_WGS84_M, GPS_Math_UTM_EN_To_Known_Datum, GPS_Math_WGS84_To_Known_Datum_M, GPS_Math_WGS84_To_UKOSMap_M
@@ -361,7 +361,7 @@ XcsvFormat::gmsd_init(Waypoint* wpt)
 {
   garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
   if (gmsd == nullptr) {
-    gmsd = garmin_fs_alloc(-1);
+    gmsd = new garmin_fs_t(-1);
     wpt->fs.FsChainAdd(gmsd);
   }
   return gmsd;

From 45961b858175b10435543753cf8cd0360e728e2d Mon Sep 17 00:00:00 2001
From: tsteven4 <13596209+tsteven4@users.noreply.github.com>
Date: Mon, 30 Oct 2023 12:39:03 -0600
Subject: [PATCH 02/11] make gmsd const for read only usage.

this prevents the possiblity of detachment of the ilinks list.
---
 garmin.cc     |  2 +-
 garmin_gpi.cc |  2 +-
 garmin_txt.cc |  4 ++--
 gdb.cc        |  6 +++---
 gdb.h         |  2 +-
 unicsv.cc     |  4 ++--
 xcsv.cc       | 16 ++++++++--------
 7 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/garmin.cc b/garmin.cc
index aafa3b209..dd04edc42 100644
--- a/garmin.cc
+++ b/garmin.cc
@@ -1275,7 +1275,7 @@ garmin_fs_garmin_after_read(const GPS_PWay way, Waypoint* wpt, const int protoid
 static void
 garmin_fs_garmin_before_write(const Waypoint* wpt, GPS_PWay way, const int protoid)
 {
-  garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+  const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
 
   (void)protoid; // unused for now.
 
diff --git a/garmin_gpi.cc b/garmin_gpi.cc
index efccc3a3d..3f9a824fb 100644
--- a/garmin_gpi.cc
+++ b/garmin_gpi.cc
@@ -700,7 +700,7 @@ GarminGPIFormat::wdata_compute_size(writer_data_t* data) const
   res = 23;  /* bounds, ... of tag 0x80008 */
 
   foreach (Waypoint* wpt, data->waypt_list) {
-    garmin_fs_t* gmsd;
+    const garmin_fs_t* gmsd;
 
     res += 12;    /* tag/sz/sub-sz */
     res += 19;    /* poi fixed size */
diff --git a/garmin_txt.cc b/garmin_txt.cc
index 3dd66e252..27d32815b 100644
--- a/garmin_txt.cc
+++ b/garmin_txt.cc
@@ -221,7 +221,7 @@ convert_datum(const Waypoint* wpt, double* dest_lat, double* dest_lon)
 static void
 enum_waypt_cb(const Waypoint* wpt)
 {
-  garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+  const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
   int wpt_class = garmin_fs_t::get_wpt_class(gmsd, 0);
   if (wpt_class < 0x80) {
     if (gtxt_flags.enum_waypoints) {		/* enumerate only */
@@ -528,7 +528,7 @@ write_waypt(const Waypoint* wpt)
 {
   const char* wpt_type;
 
-  garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+  const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
 
   int i = garmin_fs_t::get_display(gmsd, 0);
   if (i > GT_DISPLAY_MODE_MAX) {
diff --git a/gdb.cc b/gdb.cc
index c9c83f200..db3bec6a5 100644
--- a/gdb.cc
+++ b/gdb.cc
@@ -1179,7 +1179,7 @@ GdbFormat::gdb_check_waypt(Waypoint* wpt)
 
 void
 GdbFormat::write_waypoint(
-  const Waypoint* wpt, const QString& shortname, garmin_fs_t* gmsd,
+  const Waypoint* wpt, const QString& shortname, const garmin_fs_t* gmsd,
   const int icon, const int display)
 {
   char zbuf[32], ffbuf[32];
@@ -1376,7 +1376,7 @@ GdbFormat::write_route(const route_head* rte, const QString& rte_name)
       fatal(MYNAME ": Sorry, that should never happen!!!\n");
     }
 
-    garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+    const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
 
     /* extra_data may contain a modified shortname */
     gdb_write_cstr((wpt->extra_data) ? *static_cast<QString*>(wpt->extra_data) : wpt->shortname);
@@ -1549,7 +1549,7 @@ GdbFormat::write_waypoint_cb(const Waypoint* refpt)
     fout = ftmp;
 
     /* prepare the waypoint */
-    garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+    const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
 
     int wpt_class = garmin_fs_t::get_wpt_class(gmsd, -1);
     if (wpt_class == -1) {
diff --git a/gdb.h b/gdb.h
index 6697ca592..fc3497401 100644
--- a/gdb.h
+++ b/gdb.h
@@ -150,7 +150,7 @@ class GdbFormat : public Format
   void reset_short_handle(const char* defname);
   void write_header();
   static void gdb_check_waypt(Waypoint* wpt);
-  void write_waypoint(const Waypoint* wpt, const QString& shortname, garmin_fs_t* gmsd, int icon, int display);
+  void write_waypoint(const Waypoint* wpt, const QString& shortname, const garmin_fs_t* gmsd, int icon, int display);
   static void route_compute_bounds(const route_head* rte, bounds* bounds);
   void route_write_bounds(bounds* bounds) const;
   void write_route(const route_head* rte, const QString& rte_name);
diff --git a/unicsv.cc b/unicsv.cc
index 48c483213..679c19ad4 100644
--- a/unicsv.cc
+++ b/unicsv.cc
@@ -1113,7 +1113,7 @@ void
 UnicsvFormat::unicsv_waypt_enum_cb(const Waypoint* wpt)
 {
   const QString& shortname = wpt->shortname;
-  garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+  const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
 
   if (!shortname.isEmpty()) {
     unicsv_outp_flags[fld_shortname] = true;
@@ -1264,7 +1264,7 @@ UnicsvFormat::unicsv_waypt_disp_cb(const Waypoint* wpt)
   unicsv_waypt_ct++;
 
   QString shortname = wpt->shortname;
-  garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+  const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
 
   if (unicsv_datum_idx == kDautmWGS84) {
     lat = wpt->latitude;
diff --git a/xcsv.cc b/xcsv.cc
index 4a18e224f..d649fff55 100644
--- a/xcsv.cc
+++ b/xcsv.cc
@@ -1534,42 +1534,42 @@ XcsvFormat::xcsv_waypt_pr(const Waypoint* wpt)
     break;
     /* GMSD ************************************************************/
     case XcsvStyle::XT_COUNTRY: {
-      garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+      const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
       buff = QString::asprintf(fmp.printfc.constData(), CSTR(garmin_fs_t::get_country(gmsd, "")));
     }
     break;
     case XcsvStyle::XT_STATE: {
-      garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+      const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
       buff = QString::asprintf(fmp.printfc.constData(), CSTR(garmin_fs_t::get_state(gmsd, "")));
     }
     break;
     case XcsvStyle::XT_CITY: {
-      garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+      const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
       buff = QString::asprintf(fmp.printfc.constData(), CSTR(garmin_fs_t::get_city(gmsd, "")));
     }
     break;
     case XcsvStyle::XT_POSTAL_CODE: {
-      garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+      const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
       buff = QString::asprintf(fmp.printfc.constData(), CSTR(garmin_fs_t::get_postal_code(gmsd, "")));
     }
     break;
     case XcsvStyle::XT_STREET_ADDR: {
-      garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+      const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
       buff = QString::asprintf(fmp.printfc.constData(), CSTR(garmin_fs_t::get_addr(gmsd, "")));
     }
     break;
     case XcsvStyle::XT_PHONE_NR: {
-      garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+      const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
       buff = QString::asprintf(fmp.printfc.constData(), CSTR(garmin_fs_t::get_phone_nr(gmsd, "")));
     }
     break;
     case XcsvStyle::XT_FACILITY: {
-      garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+      const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
       buff = QString::asprintf(fmp.printfc.constData(), CSTR(garmin_fs_t::get_facility(gmsd, "")));
     }
     break;
     case XcsvStyle::XT_EMAIL: {
-      garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
+      const garmin_fs_t* gmsd = garmin_fs_t::find(wpt);
       buff = QString::asprintf(fmp.printfc.constData(), CSTR(garmin_fs_t::get_email(gmsd, "")));
     }
     break;

From 50e6745c20984383ef2e69ae9b555c8018dc143c Mon Sep 17 00:00:00 2001
From: tsteven4 <13596209+tsteven4@users.noreply.github.com>
Date: Mon, 30 Oct 2023 12:54:32 -0600
Subject: [PATCH 03/11] incorporate some variables and functions into
 garmin_fs_t

---
 garmin_fs.cc  | 4 ++--
 garmin_fs.h   | 9 +++++----
 garmin_txt.cc | 6 +++---
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/garmin_fs.cc b/garmin_fs.cc
index 46a857d36..8001d4ff4 100644
--- a/garmin_fs.cc
+++ b/garmin_fs.cc
@@ -33,7 +33,7 @@
 
 
 bool
-garmin_fs_convert_category(const QString& category_name, uint16_t* category)
+garmin_fs_t::convert_category(const QString& category_name, uint16_t* category)
 {
   // Is the name  "Category" followed by a number? Use that number.
   if (category_name.startsWith(u"Category ", Qt::CaseInsensitive)) {
@@ -64,7 +64,7 @@ garmin_fs_merge_category(const QString& category_name, Waypoint* waypt)
   uint16_t cat;
 
   // Attempt to get a textual category name to a category number.
-  if (!garmin_fs_convert_category(category_name, &cat)) {
+  if (!garmin_fs_t::convert_category(category_name, &cat)) {
     return false;
   }
 
diff --git a/garmin_fs.h b/garmin_fs.h
index 20c68ccff..96ec4fc65 100644
--- a/garmin_fs.h
+++ b/garmin_fs.h
@@ -96,6 +96,8 @@ struct garmin_fs_flags_t {
 
 class garmin_fs_t : public FormatSpecificData {
 public:
+  static constexpr char GMSD_SECTION_CATEGORIES[] = "Garmin Categories";
+
   garmin_fs_flags_t flags;
 
   int protocol{0};		/* ... used by device (-1 is MapSource) */
@@ -212,14 +214,13 @@ class garmin_fs_t : public FormatSpecificData {
   GEN_GMSD_STR_METHODS(email)
 
 #undef GEN_GMSD_STR_METHODS
-};
 
 /* ..convert_category: returns true=OK; false=Unable to convert category */
-bool garmin_fs_convert_category(const QString& category_name, uint16_t* category);
+static bool convert_category(const QString& category_name, uint16_t* category);
+
+};
 
 /* ..merge_category: returns true=OK; false=Unable to convert category */
 bool garmin_fs_merge_category(const QString& category_name, Waypoint* waypt);
 
-#define GMSD_SECTION_CATEGORIES "Garmin Categories"
-
 #endif
diff --git a/garmin_txt.cc b/garmin_txt.cc
index 27d32815b..7230afd0e 100644
--- a/garmin_txt.cc
+++ b/garmin_txt.cc
@@ -49,7 +49,7 @@
 
 #include "csv_util.h"              // for csv_linesplit
 #include "formspec.h"              // for FormatSpecificDataList
-#include "garmin_fs.h"             // for garmin_fs_t, garmin_fs_convert_category, GMSD_SECTION_CATEGORIES
+#include "garmin_fs.h"             // for garmin_fs_t, GMSD_SECTION_CATEGORIES
 #include "garmin_tables.h"         // for gt_display_modes_e, gt_find_desc_from_icon_number, gt_find_icon_number_from_desc, gt_get_mps_grid_longname, gt_lookup_datum_index, gt_lookup_grid_type, GDB, gt_get_icao_cc, gt_get_icao_country, gt_get_mps_datum_name, gt_waypt_class_names, GT_DISPLAY_MODE...
 #include "inifile.h"               // for inifile_readstr
 #include "jeeps/gpsmath.h"         // for GPS_Math_Known_Datum_To_UTM_EN, GPS_Math_WGS84_To_Known_Datum_M, GPS_Math_WGS84_To_Swiss_EN, GPS_Math_WGS84_To_UKOSMap_M
@@ -403,7 +403,7 @@ print_categories(uint16_t categories)
       QString c;
       if (global_opts.inifile != nullptr) {
         QString key = QString::number(i + 1);
-        c = inifile_readstr(global_opts.inifile, GMSD_SECTION_CATEGORIES, key);
+        c = inifile_readstr(global_opts.inifile, garmin_fs_t::GMSD_SECTION_CATEGORIES, key);
       }
 
       *fout << QString::asprintf("%s", (count++ > 0) ? "," : "");
@@ -965,7 +965,7 @@ parse_categories(const QString& str)
     QString cin = catstring.trimmed();
     if (!cin.isEmpty()) {
       uint16_t val;
-      if (!garmin_fs_convert_category(cin, &val)) {
+      if (!garmin_fs_t::convert_category(cin, &val)) {
         warning(MYNAME ": Unable to convert category \"%s\" at line %d!\n", qPrintable(cin), current_line);
       } else {
         res = res | val;

From 96f59f412403712bc324e263bdbdb4596c90c935 Mon Sep 17 00:00:00 2001
From: tsteven4 <13596209+tsteven4@users.noreply.github.com>
Date: Mon, 30 Oct 2023 16:20:23 -0600
Subject: [PATCH 04/11] unify garmin category conversions.

---
 garmin_fs.cc                   | 57 ++++++++++++++++++++--------------
 garmin_fs.h                    | 19 +++++++-----
 garmin_txt.cc                  | 42 +++++++------------------
 gpx.cc                         | 15 ++++-----
 reference/garmincategories.gpx | 35 +++++++++++++++++++++
 reference/garmincategories.txt |  7 +++++
 testo.d/gpx.test               |  7 +++++
 util.cc                        |  4 +--
 8 files changed, 115 insertions(+), 71 deletions(-)
 create mode 100644 reference/garmincategories.gpx
 create mode 100644 reference/garmincategories.txt

diff --git a/garmin_fs.cc b/garmin_fs.cc
index 8001d4ff4..525523005 100644
--- a/garmin_fs.cc
+++ b/garmin_fs.cc
@@ -29,52 +29,61 @@
 #include "inifile.h"  // for inifile_readstr
 
 
-#define MYNAME "garmin_fs"
-
-
-bool
-garmin_fs_t::convert_category(const QString& category_name, uint16_t* category)
+std::optional<uint16_t>
+garmin_fs_t::convert_category(const QString& category_name)
 {
+  std::optional<uint16_t> category;
+
   // Is the name  "Category" followed by a number? Use that number.
   if (category_name.startsWith(u"Category ", Qt::CaseInsensitive)) {
     bool ok;
     int i = category_name.mid(9).toInt(&ok);
     if (ok && (i >= 1) && (i <= 16)) {
-      *category = (1 << --i);
-      return true;
+      category = (1 << --i);
+      return category;
     }
   }
   if (global_opts.inifile != nullptr) {
     // Do we have a gpsbabel.ini that maps category names to category #'s?
     for (int i = 0; i < 16; i++) {
       QString key = QString::number(i + 1);
-      QString c = inifile_readstr(global_opts.inifile, GMSD_SECTION_CATEGORIES, key);
+      QString c = inifile_readstr(global_opts.inifile, kGmsdSectionCategories, key);
       if (c.compare(category_name, Qt::CaseInsensitive) == 0) {
-        *category = (1 << i);
-        return true;
+        category = (1 << i);
+        return category;
       }
     }
   }
-  return false;
+  return category;
 }
 
-bool
-garmin_fs_merge_category(const QString& category_name, Waypoint* waypt)
+QStringList
+garmin_fs_t::print_categories(uint16_t categories)
 {
-  uint16_t cat;
+  QStringList categoryList;
 
-  // Attempt to get a textual category name to a category number.
-  if (!garmin_fs_t::convert_category(category_name, &cat)) {
-    return false;
+  if (categories == 0) {
+    return categoryList;
   }
 
-  garmin_fs_t* gmsd = garmin_fs_t::find(waypt);
-  cat = cat | (garmin_fs_t::get_category(gmsd, 0));
+  for (int i = 0; i < 16; i++) {
+    if ((categories & 1) != 0) {
+      QString c;
+      if (global_opts.inifile != nullptr) {
+        QString key = QString::number(i + 1);
+        c = inifile_readstr(global_opts.inifile, kGmsdSectionCategories, key);
+      }
+
+      if (c.isNull()) {
+        categoryList << QString::asprintf("Category %d", i+1);
+      }
+//				*fout << QString::asprintf("%s", gps_categories[i]);
+      else {
+        categoryList << c;
+      }
 
-  if (gmsd == nullptr) {
-    gmsd = new garmin_fs_t(-1);
-    waypt->fs.FsChainAdd(gmsd);
+    }
+    categories = categories >> 1;
   }
-  garmin_fs_t::set_category(gmsd, cat);
-  return true;
+  return categoryList;
 }
diff --git a/garmin_fs.h b/garmin_fs.h
index 96ec4fc65..ac74e8957 100644
--- a/garmin_fs.h
+++ b/garmin_fs.h
@@ -25,6 +25,7 @@
 #define GARMIN_FS_H
 
 #include <cstdint>     // for int32_t, int16_t, uint16_t
+#include <optional>    // for optional
 
 #include <QList>       // for QList
 #include <QString>     // for QString
@@ -96,7 +97,7 @@ struct garmin_fs_flags_t {
 
 class garmin_fs_t : public FormatSpecificData {
 public:
-  static constexpr char GMSD_SECTION_CATEGORIES[] = "Garmin Categories";
+  /* Data Members */
 
   garmin_fs_flags_t flags;
 
@@ -125,10 +126,12 @@ class garmin_fs_t : public FormatSpecificData {
   char subclass[22]{};
 #endif
 
-public:
+  /* Special Member Functions */
+
   garmin_fs_t() : FormatSpecificData(kFsGmsd) {}
   explicit garmin_fs_t(int p) : garmin_fs_t() {protocol = p;}
 
+  /* Member Functions */
 
   garmin_fs_t* clone() const override
   {
@@ -139,6 +142,9 @@ class garmin_fs_t : public FormatSpecificData {
     return reinterpret_cast<garmin_fs_t*>(wpt->fs.FsChainFind(kFsGmsd));
   }
 
+  static std::optional<uint16_t> convert_category(const QString& category_name);
+  static QStringList print_categories(uint16_t categories);
+
 #define GEN_GMSD_METHODS(field) \
   static bool has_##field(const garmin_fs_t* gmsd) \
   { \
@@ -215,12 +221,9 @@ class garmin_fs_t : public FormatSpecificData {
 
 #undef GEN_GMSD_STR_METHODS
 
-/* ..convert_category: returns true=OK; false=Unable to convert category */
-static bool convert_category(const QString& category_name, uint16_t* category);
+private:
+  /* Constants */
 
+  static constexpr char kGmsdSectionCategories[] = "Garmin Categories";
 };
-
-/* ..merge_category: returns true=OK; false=Unable to convert category */
-bool garmin_fs_merge_category(const QString& category_name, Waypoint* waypt);
-
 #endif
diff --git a/garmin_txt.cc b/garmin_txt.cc
index 7230afd0e..ff8bdf260 100644
--- a/garmin_txt.cc
+++ b/garmin_txt.cc
@@ -33,6 +33,7 @@
 #include <cstdlib>                 // for abs
 #include <cstring>                 // for strstr, strlen
 #include <ctime>                   // for time_t, gmtime, localtime, strftime
+#include <optional>                // for optional
 #include <utility>                 // for pair, make_pair
 
 #include <QByteArray>              // for QByteArray
@@ -49,7 +50,7 @@
 
 #include "csv_util.h"              // for csv_linesplit
 #include "formspec.h"              // for FormatSpecificDataList
-#include "garmin_fs.h"             // for garmin_fs_t, GMSD_SECTION_CATEGORIES
+#include "garmin_fs.h"             // for garmin_fs_t
 #include "garmin_tables.h"         // for gt_display_modes_e, gt_find_desc_from_icon_number, gt_find_icon_number_from_desc, gt_get_mps_grid_longname, gt_lookup_datum_index, gt_lookup_grid_type, GDB, gt_get_icao_cc, gt_get_icao_country, gt_get_mps_datum_name, gt_waypt_class_names, GT_DISPLAY_MODE...
 #include "inifile.h"               // for inifile_readstr
 #include "jeeps/gpsmath.h"         // for GPS_Math_Known_Datum_To_UTM_EN, GPS_Math_WGS84_To_Known_Datum_M, GPS_Math_WGS84_To_Swiss_EN, GPS_Math_WGS84_To_UKOSMap_M
@@ -393,30 +394,9 @@ print_date_and_time(const time_t time, const bool time_only)
 static void
 print_categories(uint16_t categories)
 {
-  if (categories == 0) {
-    return;
-  }
-
-  int count = 0;
-  for (int i = 0; i < 16; i++) {
-    if ((categories & 1) != 0) {
-      QString c;
-      if (global_opts.inifile != nullptr) {
-        QString key = QString::number(i + 1);
-        c = inifile_readstr(global_opts.inifile, garmin_fs_t::GMSD_SECTION_CATEGORIES, key);
-      }
-
-      *fout << QString::asprintf("%s", (count++ > 0) ? "," : "");
-      if (c.isNull()) {
-        *fout << QString::asprintf("Category %d", i+1);
-      }
-//				*fout << QString::asprintf("%s", gps_categories[i]);
-      else {
-        *fout << c;
-      }
-
-    }
-    categories = categories >> 1;
+  const QStringList categoryList = garmin_fs_t::print_categories(categories);
+  if (!categoryList.isEmpty()) {
+    *fout << categoryList.join(',');
   }
 }
 
@@ -902,7 +882,7 @@ strftime_to_timespec(const char* s)
           q += "yyyy";
           continue;
         case 'H':
-          q += "hh";
+          q += "HH";
           continue;
         case 'M':
           q += "mm";
@@ -931,8 +911,11 @@ strftime_to_timespec(const char* s)
         case 'F':
           q += "yyyy-MM-dd";
           continue;
+        case 'p':
+          q += "AP";
+          continue;
         default:
-          q += s[i+1];
+          warning(MYNAME ": omitting unknown strptime conversion \"%%%c\" in \"%s\"\n", s[i], s);
           break;
         }
       }
@@ -964,11 +947,10 @@ parse_categories(const QString& str)
   for (const auto& catstring : catstrings) {
     QString cin = catstring.trimmed();
     if (!cin.isEmpty()) {
-      uint16_t val;
-      if (!garmin_fs_t::convert_category(cin, &val)) {
+      if (std::optional<uint16_t> cat = garmin_fs_t::convert_category(cin); !cat.has_value()) {
         warning(MYNAME ": Unable to convert category \"%s\" at line %d!\n", qPrintable(cin), current_line);
       } else {
-        res = res | val;
+        res = res | *cat;
       }
     }
   }
diff --git a/gpx.cc b/gpx.cc
index 787b68131..176ecc676 100644
--- a/gpx.cc
+++ b/gpx.cc
@@ -47,7 +47,7 @@
 #include <QtGlobal>                         // for qAsConst, QAddConst<>::Type
 
 #include "defs.h"
-#include "garmin_fs.h"                      // for garmin_fs_t, garmin_ilink_t, garmin_fs_merge_category
+#include "garmin_fs.h"                      // for garmin_fs_t, garmin_ilink_t
 #include "garmin_tables.h"                  // for gt_color_index_by_rgb, gt_color_name, gt_color_value_by_name
 #include "geocache.h"                       // for Geocache, Geocache::UtfSt...
 #include "mkshort.h"                        // for MakeShort
@@ -243,7 +243,10 @@ GpxFormat::tag_garmin_fs(tag_type tag, const QString& text, Waypoint* waypt)
     }
     break;
   case tag_type::garmin_wpt_category:
-    if (!garmin_fs_merge_category(text, waypt)) {
+    if (auto cat = garmin_fs_t::convert_category(text); cat.has_value()) {
+      cat = *cat | (garmin_fs_t::get_category(gmsd, 0));
+      garmin_fs_t::set_category(gmsd, *cat);
+    } else {
       // There's nothing a user can really do about this (well, they could
       // create a gpsbabel.ini that mapped them to garmin category numbers
       // but that feature is so obscure and used in so few outputs that
@@ -1379,11 +1382,9 @@ GpxFormat::gpx_write_common_extensions(const Waypoint* waypointp, const gpx_poin
       if (garmin_fs_t::has_category(gmsd)) {
         uint16_t cx = gmsd->category;
         writer->stackStartElement(QStringLiteral("gpxx:Categories"));
-        for (int i = 0; i < 16; i++) {
-          if (cx & 1) {
-            writer->stackTextElement(QStringLiteral("gpxx:Category"), QStringLiteral("Category %1").arg(i+1));
-          }
-          cx = cx >> 1;
+        const QStringList categoryList = garmin_fs_t::print_categories(cx);
+        for (const auto& text : categoryList) {
+            writer->stackTextElement(QStringLiteral("gpxx:Category"), text);
         }
         writer->stackEndElement(); // gpxx:Categories
       }
diff --git a/reference/garmincategories.gpx b/reference/garmincategories.gpx
new file mode 100644
index 000000000..95b140d19
--- /dev/null
+++ b/reference/garmincategories.gpx
@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<gpx version="1.1" creator="GPSBabel - https://www.gpsbabel.org" xmlns="http://www.topografix.com/GPX/1/1" xmlns:gpxx="http://www.garmin.com/xmlschemas/GpxExtensions/v3" xmlns:gpxtpx="http://www.garmin.com/xmlschemas/TrackPointExtension/v1">
+  <metadata>
+    <time>1970-01-01T00:00:00Z</time>
+    <bounds minlat="39.973869717" minlon="-105.498962400" maxlat="40.003967283" maxlon="-105.465850367"/>
+  </metadata>
+  <wpt lat="39.973869717" lon="-105.465850367">
+    <time>2013-03-09T20:45:12Z</time>
+    <name>Hwy 119</name>
+    <cmt>The Diagonal</cmt>
+    <desc>The Diagonal</desc>
+    <sym>Flag, Blue</sym>
+    <extensions>
+      <gpxx:WaypointExtension>
+        <gpxx:DisplayMode>SymbolAndName</gpxx:DisplayMode>
+        <gpxx:Categories>
+          <gpxx:Category>Slow food</gpxx:Category>
+          <gpxx:Category>Category 11</gpxx:Category>
+        </gpxx:Categories>
+      </gpxx:WaypointExtension>
+    </extensions>
+  </wpt>
+  <wpt lat="40.003967283" lon="-105.498962400">
+    <time>2013-03-09T20:45:02Z</time>
+    <name>Hwy 72</name>
+    <cmt>The Peak to Peak</cmt>
+    <desc>The Peak to Peak</desc>
+    <sym>Flag, Blue</sym>
+    <extensions>
+      <gpxx:WaypointExtension>
+        <gpxx:DisplayMode>SymbolAndName</gpxx:DisplayMode>
+      </gpxx:WaypointExtension>
+    </extensions>
+  </wpt>
+</gpx>
diff --git a/reference/garmincategories.txt b/reference/garmincategories.txt
new file mode 100644
index 000000000..b7ec5292c
--- /dev/null
+++ b/reference/garmincategories.txt
@@ -0,0 +1,7 @@
+Grid	Lat/Lon hddd°mm.mmm'
+Datum	WGS 84
+
+Header	Name	Description	Type	Position	Altitude	Depth	Proximity	Temperature	Display Mode	Color	Symbol	Facility	City	State	Country	Date Modified	Link	Categories
+
+Waypoint	Hwy 119	The Diagonal	User Waypoint	N39 58.432183 W105 27.951022					Symbol & Name	Unknown	Flag, Blue					09.03.2013 13:45:12 PM 		Slow food,Category 11
+Waypoint	Hwy 72	The Peak to Peak	User Waypoint	N40 00.238037 W105 29.937744					Symbol & Name	Unknown	Flag, Blue					09.03.2013 13:45:02 PM 		
diff --git a/testo.d/gpx.test b/testo.d/gpx.test
index 85581adf4..f3b61cf25 100644
--- a/testo.d/gpx.test
+++ b/testo.d/gpx.test
@@ -79,6 +79,13 @@ compare ${REFERENCE}/gpxpassthrough10~gpx.gpx ${TMPDIR}/gpxpassthrough10~gpx.gpx
 gpsbabel -i gpx -f ${REFERENCE}/gpxpassthrough11.gpx -o gpx -F ${TMPDIR}/gpxpassthrough11~gpx.gpx
 compare ${REFERENCE}/gpxpassthrough11~gpx.gpx ${TMPDIR}/gpxpassthrough11~gpx.gpx
 
+# garmin specific categories
+gpsbabel -p gpsbabel-sample.ini -i gpx -f ${REFERENCE}/garmincategories.gpx  -o garmin_txt -F ${TMPDIR}/garmincategories~gpx.txt
+compare ${REFERENCE}/garmincategories.txt ${TMPDIR}/garmincategories~gpx.txt
+
+gpsbabel -p gpsbabel-sample.ini -i garmin_txt -f ${REFERENCE}/garmincategories.txt -o gpx,garminextensions -F ${TMPDIR}/garmincategories~txt.gpx
+compare ${REFERENCE}/garmincategories.gpx ${TMPDIR}/garmincategories~txt.gpx
+
 if [ -z "${VALGRIND}" ]; then
   set -e
   if command -v xmllint > /dev/null;
diff --git a/util.cc b/util.cc
index e1723f533..c625e95d4 100644
--- a/util.cc
+++ b/util.cc
@@ -623,7 +623,7 @@ convert_human_date_format(const char* human_datef)
     }
 
     if (okay == 0) {
-      fatal("Invalid character \"%c\" in date format!", *cin);
+      fatal("Invalid character \"%c\" in date format \"%s\"!\n", *cin, human_datef);
     }
   }
   QString rv(result);
@@ -717,7 +717,7 @@ convert_human_time_format(const char* human_timef)
     }
 
     if (okay == 0) {
-      fatal("Invalid character \"%c\" in time format!", *cin);
+      fatal("Invalid character \"%c\" in time format \"%s\"!\n", *cin, human_timef);
     }
   }
   QString rv(result);

From 573d1689abfbc4cf1e09d4afd1f474f995158090 Mon Sep 17 00:00:00 2001
From: tsteven4 <13596209+tsteven4@users.noreply.github.com>
Date: Mon, 30 Oct 2023 16:54:16 -0600
Subject: [PATCH 05/11] fiddle with test time zone sensitivity.

---
 testo.d/gpx.test | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/testo.d/gpx.test b/testo.d/gpx.test
index f3b61cf25..ef9c1cc55 100644
--- a/testo.d/gpx.test
+++ b/testo.d/gpx.test
@@ -80,7 +80,7 @@ gpsbabel -i gpx -f ${REFERENCE}/gpxpassthrough11.gpx -o gpx -F ${TMPDIR}/gpxpass
 compare ${REFERENCE}/gpxpassthrough11~gpx.gpx ${TMPDIR}/gpxpassthrough11~gpx.gpx
 
 # garmin specific categories
-gpsbabel -p gpsbabel-sample.ini -i gpx -f ${REFERENCE}/garmincategories.gpx  -o garmin_txt -F ${TMPDIR}/garmincategories~gpx.txt
+gpsbabel -p gpsbabel-sample.ini -i gpx -f ${REFERENCE}/garmincategories.gpx  -o garmin_txt,utc=-7 -F ${TMPDIR}/garmincategories~gpx.txt
 compare ${REFERENCE}/garmincategories.txt ${TMPDIR}/garmincategories~gpx.txt
 
 gpsbabel -p gpsbabel-sample.ini -i garmin_txt -f ${REFERENCE}/garmincategories.txt -o gpx,garminextensions -F ${TMPDIR}/garmincategories~txt.gpx

From 99dd6d70c13eaa0979b7512e0e3e17ad9ad2032a Mon Sep 17 00:00:00 2001
From: tsteven4 <13596209+tsteven4@users.noreply.github.com>
Date: Mon, 30 Oct 2023 18:08:58 -0600
Subject: [PATCH 06/11] add utc option for garmin_txt reader.

---
 garmin_txt.cc    | 35 ++++++++++++++++++++++++++---------
 testo.d/gpx.test |  2 +-
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/garmin_txt.cc b/garmin_txt.cc
index ff8bdf260..c0181d311 100644
--- a/garmin_txt.cc
+++ b/garmin_txt.cc
@@ -720,6 +720,28 @@ track_disp_wpt_cb(const Waypoint* wpt)
 * %%%        global callbacks called by gpsbabel main process              %%% *
 *******************************************************************************/
 
+static void
+garmin_txt_utc_option()
+{
+  if (opt_utc != nullptr) {
+    if (case_ignore_strcmp(opt_utc, "utc") == 0) {
+      utc_offs = 0;
+    } else {
+      utc_offs = xstrtoi(opt_utc, nullptr, 10);
+    }
+    utc_offs *= (60 * 60);
+    gtxt_flags.utc = 1;
+  }
+}
+
+static void
+garmin_txt_adjust_time(QDateTime& dt)
+{
+  if (gtxt_flags.utc) {
+    dt = dt.toUTC().addSecs(utc_offs - dt.offsetFromUtc());
+  }
+}
+
 static void
 garmin_txt_wr_init(const QString& fname)
 {
@@ -766,15 +788,7 @@ garmin_txt_wr_init(const QString& fname)
     datum_index = gt_lookup_datum_index(datum_str, MYNAME);
   }
 
-  if (opt_utc != nullptr) {
-    if (case_ignore_strcmp(opt_utc, "utc") == 0) {
-      utc_offs = 0;
-    } else {
-      utc_offs = xstrtoi(opt_utc, nullptr, 10);
-    }
-    utc_offs *= (60 * 60);
-    gtxt_flags.utc = 1;
-  }
+  garmin_txt_utc_option();
 }
 
 static void
@@ -1166,6 +1180,7 @@ parse_waypoint(const QStringList& lineparts)
       break;
     case 16:
       if (QDateTime dt = parse_date_and_time(str); dt.isValid()) {
+        garmin_txt_adjust_time(dt);
         wpt->SetCreationTime(dt);
       }
     break;
@@ -1301,6 +1316,7 @@ parse_track_waypoint(const QStringList& lineparts)
       break;
     case 2:
       if (QDateTime dt = parse_date_and_time(str); dt.isValid()) {
+        garmin_txt_adjust_time(dt);
         wpt->SetCreationTime(dt);
       }
     break;
@@ -1349,6 +1365,7 @@ garmin_txt_rd_init(const QString& fname)
   grid_index = (grid_type) -1;
 
   init_date_and_time_format();
+  garmin_txt_utc_option();
 }
 
 static void
diff --git a/testo.d/gpx.test b/testo.d/gpx.test
index ef9c1cc55..f917b2a2e 100644
--- a/testo.d/gpx.test
+++ b/testo.d/gpx.test
@@ -83,7 +83,7 @@ compare ${REFERENCE}/gpxpassthrough11~gpx.gpx ${TMPDIR}/gpxpassthrough11~gpx.gpx
 gpsbabel -p gpsbabel-sample.ini -i gpx -f ${REFERENCE}/garmincategories.gpx  -o garmin_txt,utc=-7 -F ${TMPDIR}/garmincategories~gpx.txt
 compare ${REFERENCE}/garmincategories.txt ${TMPDIR}/garmincategories~gpx.txt
 
-gpsbabel -p gpsbabel-sample.ini -i garmin_txt -f ${REFERENCE}/garmincategories.txt -o gpx,garminextensions -F ${TMPDIR}/garmincategories~txt.gpx
+gpsbabel -p gpsbabel-sample.ini -i garmin_txt,utc=-7 -f ${REFERENCE}/garmincategories.txt -o gpx,garminextensions -F ${TMPDIR}/garmincategories~txt.gpx
 compare ${REFERENCE}/garmincategories.gpx ${TMPDIR}/garmincategories~txt.gpx
 
 if [ -z "${VALGRIND}" ]; then

From 6221a7789cdd83b58a30fa9327d7dd54617d628c Mon Sep 17 00:00:00 2001
From: tsteven4 <13596209+tsteven4@users.noreply.github.com>
Date: Mon, 30 Oct 2023 18:18:50 -0600
Subject: [PATCH 07/11] correct sign of adjustment

---
 garmin_txt.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/garmin_txt.cc b/garmin_txt.cc
index c0181d311..8c3d2875d 100644
--- a/garmin_txt.cc
+++ b/garmin_txt.cc
@@ -738,7 +738,7 @@ static void
 garmin_txt_adjust_time(QDateTime& dt)
 {
   if (gtxt_flags.utc) {
-    dt = dt.toUTC().addSecs(utc_offs - dt.offsetFromUtc());
+    dt = dt.toUTC().addSecs(dt.offsetFromUtc() - utc_offs);
   }
 }
 

From 6a45ee2c43f7596ac1f7a9f3ee22f9403d0c1c8f Mon Sep 17 00:00:00 2001
From: tsteven4 <13596209+tsteven4@users.noreply.github.com>
Date: Tue, 31 Oct 2023 19:36:43 -0600
Subject: [PATCH 08/11] simpify formatting of date/time in garmin_txt.

---
 defs.h                         |   2 -
 garmin_txt.cc                  | 170 +++++++++------------------------
 gpsbabel-sample.ini            |   4 +-
 reference/format3.txt          |   4 +-
 reference/garmincategories.txt |   4 +-
 reference/help.txt             |   4 +-
 util.cc                        | 167 +-------------------------------
 7 files changed, 56 insertions(+), 299 deletions(-)

diff --git a/defs.h b/defs.h
index 1ab851799..3c39d2408 100644
--- a/defs.h
+++ b/defs.h
@@ -966,8 +966,6 @@ QDateTime dotnet_time_to_qdatetime(long long dotnet);
 long long qdatetime_to_dotnet_time(const QDateTime& dt);
 QString strip_html(const QString& utfstring);
 QString strip_nastyhtml(const QString& in);
-QString convert_human_date_format(const char* human_datef);	/* "MM,YYYY,DD" -> "%m,%Y,%d" */
-QString convert_human_time_format(const char* human_timef);	/* "HH+mm+ss"   -> "%H+%M+%S" */
 QString pretty_deg_format(double lat, double lon, char fmt, const char* sep, bool html);    /* decimal ->  dd.dddd or dd mm.mmm or dd mm ss */
 
 QString get_filename(const QString& fname);			/* extract the filename portion */
diff --git a/garmin_txt.cc b/garmin_txt.cc
index 8c3d2875d..fff8694b1 100644
--- a/garmin_txt.cc
+++ b/garmin_txt.cc
@@ -29,10 +29,9 @@
 #include <cctype>                  // for toupper
 #include <cmath>                   // for fabs, floor
 #include <cstdint>                 // for uint16_t
-#include <cstdio>                  // for sscanf, fprintf, snprintf, stderr
-#include <cstdlib>                 // for abs
-#include <cstring>                 // for strstr, strlen
-#include <ctime>                   // for time_t, gmtime, localtime, strftime
+#include <cstdio>                  // for sscanf, fprintf, stderr
+#include <cstdlib>                 // for abs, div
+#include <cstring>                 // for strstr
 #include <optional>                // for optional
 #include <utility>                 // for pair, make_pair
 
@@ -52,7 +51,6 @@
 #include "formspec.h"              // for FormatSpecificDataList
 #include "garmin_fs.h"             // for garmin_fs_t
 #include "garmin_tables.h"         // for gt_display_modes_e, gt_find_desc_from_icon_number, gt_find_icon_number_from_desc, gt_get_mps_grid_longname, gt_lookup_datum_index, gt_lookup_grid_type, GDB, gt_get_icao_cc, gt_get_icao_country, gt_get_mps_datum_name, gt_waypt_class_names, GT_DISPLAY_MODE...
-#include "inifile.h"               // for inifile_readstr
 #include "jeeps/gpsmath.h"         // for GPS_Math_Known_Datum_To_UTM_EN, GPS_Math_WGS84_To_Known_Datum_M, GPS_Math_WGS84_To_Swiss_EN, GPS_Math_WGS84_To_UKOSMap_M
 #include "src/core/datetime.h"     // for DateTime
 #include "src/core/logging.h"      // for Fatal
@@ -84,7 +82,7 @@ static const char* datum_str;
 static int current_line;
 static QString date_time_format;
 static int precision = 3;
-static time_t utc_offs = 0;
+static int utc_offs = 0;
 static gtxt_flags_t gtxt_flags;
 
 enum header_type {
@@ -122,7 +120,7 @@ static std::array<QList<std::pair<QString, int>>, unknown_header> header_mapping
 static QStringList header_column_names;
 
 static constexpr double kGarminUnknownAlt = 1.0e25;
-static constexpr char kDefaultDateFormat[] = "dd/mm/yyyy";
+static constexpr char kDefaultDateFormat[] = "dd/MM/yyyy";
 static constexpr char kDefaultTimeFormat[] = "HH:mm:ss";
 
 static bool is_valid_alt(double alt)
@@ -141,13 +139,13 @@ static char* opt_grid = nullptr;
 
 static
 QVector<arglist_t> garmin_txt_args = {
-  {"date",  &opt_date_format, "Read/Write date format (i.e. yyyy/mm/dd)", nullptr, ARGTYPE_STRING, ARG_NOMINMAX, nullptr},
+  {"date",  &opt_date_format, "Read/Write date format (e.g. yyyy/MM/dd)", nullptr, ARGTYPE_STRING, ARG_NOMINMAX, nullptr},
   {"datum", &opt_datum, 	    "GPS datum (def. WGS 84)", "WGS 84", ARGTYPE_STRING, ARG_NOMINMAX, nullptr},
   {"dist",  &opt_dist,        "Distance unit [m=metric, s=statute]", "m", ARGTYPE_STRING, ARG_NOMINMAX, nullptr},
   {"grid",  &opt_grid,        "Write position using this grid.", nullptr, ARGTYPE_STRING, ARG_NOMINMAX, nullptr},
   {"prec",  &opt_precision,   "Precision of coordinates", "3", ARGTYPE_INT, ARG_NOMINMAX, nullptr},
   {"temp",  &opt_temp,        "Temperature unit [c=Celsius, f=Fahrenheit]", "c", ARGTYPE_STRING, ARG_NOMINMAX, nullptr},
-  {"time",  &opt_time_format, "Read/Write time format (i.e. HH:mm:ss xx)", nullptr, ARGTYPE_STRING, ARG_NOMINMAX, nullptr},
+  {"time",  &opt_time_format, "Read/Write time format (e.g. HH:mm:ss)", nullptr, ARGTYPE_STRING, ARG_NOMINMAX, nullptr},
   {"utc",   &opt_utc,         "Write timestamps with offset x to UTC time", nullptr, ARGTYPE_INT, "-23", "+23", nullptr},
 };
 
@@ -155,8 +153,8 @@ class PathInfo
 {
 public:
   double length {0};
-  time_t start {0};
-  time_t time {0};
+  QDateTime start;
+  int time {0};
   double speed {0};
   double total {0};
   int count {0};
@@ -191,16 +189,9 @@ get_option_val(const char* option, const char* def)
 static void
 init_date_and_time_format()
 {
-  // This is old, and weird, code.. date_time_format is a global that's
-  // explicitly malloced and freed elsewhere. This isn't very C++ at all,
-  // but this format is on its deathbead for deprecation.
   const char* d = get_option_val(opt_date_format, kDefaultDateFormat);
-  QString d1 = convert_human_date_format(d);
-
   const char* t = get_option_val(opt_time_format, kDefaultTimeFormat);
-  QString t1 = convert_human_time_format(t);
-
-  date_time_format = QStringLiteral("%1 %2").arg(d1, t1);
+  date_time_format = QStringLiteral("%1 %2").arg(d, t);
 }
 
 static void
@@ -264,11 +255,11 @@ prework_wpt_cb(const Waypoint* wpt)
   const Waypoint* prev = cur_info->prev_wpt;
 
   if (prev != nullptr) {
-    cur_info->time += (wpt->GetCreationTime().toTime_t() - prev->GetCreationTime().toTime_t());
+    cur_info->time += prev->GetCreationTime().secsTo(wpt->GetCreationTime());
     cur_info->length += waypt_distance_ex(prev, wpt);
   } else {
     cur_info->first_wpt = wpt;
-    cur_info->start = wpt->GetCreationTime().toTime_t();
+    cur_info->start = wpt->GetCreationTime();
   }
   cur_info->prev_wpt = wpt;
   cur_info->count++;
@@ -365,30 +356,37 @@ print_position(const Waypoint* wpt)
 }
 
 static void
-print_date_and_time(const time_t time, const bool time_only)
+print_duration(int time)
 {
-  std::tm tm{};
-  char tbuf[32];
-
   if (time < 0) {
     *fout << "\t";
     return;
   }
-  if (time_only) {
-    tm = *gmtime(&time);
-    snprintf(tbuf, sizeof(tbuf), "%d:%02d:%02d", tm.tm_hour, tm.tm_min, tm.tm_sec);
-    *fout << QString::asprintf("%s", tbuf);
-  } else if (time != 0) {
-    if (gtxt_flags.utc) {
-      time_t t = time + utc_offs;
-      tm = *gmtime(&t);
-    } else {
-      tm = *localtime(&time);
-    }
-    strftime(tbuf, sizeof(tbuf), CSTR(date_time_format), &tm);
-    *fout << QString::asprintf("%s ", tbuf);
+#if 1
+  // perhaps durations can be longer than the max QTime of 23:59:59
+  auto res = std::div(time, 60);
+  auto sec = res.rem;
+  res = std::div(res.quot, 60);
+  *fout << QString::asprintf("%d:%02d:%02d\t", res.quot, res.rem, sec);
+#else
+  QTime qt = QTime(0, 0).addSecs(time);
+  *fout << qt.toString("H:mm:ss\t");
+#endif
+}
+
+static void
+print_date_and_time(const QDateTime& dt)
+{
+  if (!dt.isValid()) {
+    *fout << "\t";
+    return;
   }
-  *fout << "\t";
+  if (gtxt_flags.utc) {
+    *fout << dt.toUTC().addSecs(utc_offs).toString(date_time_format);
+  } else {
+    *fout << dt.toLocalTime().toString(date_time_format);
+  }
+  *fout << " \t";
 }
 
 static void
@@ -445,7 +443,7 @@ print_distance(const double distance, const bool no_scale, const bool with_tab,
 }
 
 static void
-print_speed(const double distance, const time_t time)
+print_speed(const double distance, int time)
 {
   double dist = distance;
   const char* unit;
@@ -577,7 +575,7 @@ write_waypt(const Waypoint* wpt)
   print_string("%s\t", garmin_fs_t::get_state(gmsd, ""));
   const char* country = gt_get_icao_country(garmin_fs_t::get_cc(gmsd, ""));
   print_string("%s\t", (country != nullptr) ? country : "");
-  print_date_and_time(wpt->GetCreationTime().toTime_t(), false);
+  print_date_and_time(wpt->GetCreationTime());
   if (wpt->HasUrlLink()) {
     UrlLink l = wpt->GetUrlLink();
     print_string("%s\t", l.url_);
@@ -658,8 +656,8 @@ track_disp_hdr_cb(const route_head* track)
     *fout << QStringLiteral("\r\n\r\nHeader\t%1\r\n").arg(headers[track_header]);
   }
   print_string("\r\nTrack\t%s\t", track->rte_name);
-  print_date_and_time(cur_info->start, false);
-  print_date_and_time(cur_info->time, true);
+  print_date_and_time(cur_info->start);
+  print_duration(cur_info->time);
   print_distance(cur_info->length, false, true, 0);
   print_speed(cur_info->length, cur_info->time);
   if (track->rte_urls.HasUrlLink()) {
@@ -680,13 +678,13 @@ static void
 track_disp_wpt_cb(const Waypoint* wpt)
 {
   const Waypoint* prev = cur_info->prev_wpt;
-  time_t delta;
+  int delta;
   double dist;
 
   *fout << "Trackpoint\t";
 
   print_position(wpt);
-  print_date_and_time(wpt->GetCreationTime().toTime_t(), false);
+  print_date_and_time(wpt->GetCreationTime());
   if (is_valid_alt(wpt->altitude)) {
     print_distance(wpt->altitude, true, false, 0);
   }
@@ -699,7 +697,7 @@ track_disp_wpt_cb(const Waypoint* wpt)
 
   if (prev != nullptr) {
     *fout << "\t";
-    delta = wpt->GetCreationTime().toTime_t() - prev->GetCreationTime().toTime_t();
+    delta = prev->GetCreationTime().secsTo(wpt->GetCreationTime());
     float temp = wpt->temperature_value_or(-999);
     if (temp != -999) {
       print_temperature(temp);
@@ -707,7 +705,7 @@ track_disp_wpt_cb(const Waypoint* wpt)
     *fout << "\t";
     dist = waypt_distance_ex(prev, wpt);
     print_distance(dist, false, true, 0);
-    print_date_and_time(delta, true);
+    print_duration(delta);
     print_speed(dist, delta);
     print_course(prev, wpt);
   }
@@ -868,88 +866,12 @@ free_headers()
                 [](auto& list)->void { list.clear(); });
 }
 
-// Super simple attempt to convert strftime/strptime spec to Qt spec.
-// This misses a LOT of cases and vagaries, but the reality is that we
-// see very few date formats here.
-static QString
-strftime_to_timespec(const char* s)
-{
-  QString q;
-  int l = strlen(s);
-  q.reserve(l * 2); // no penalty if our guess is wrong.
-
-  for (int i = 0; i < l; i++) {
-    switch (s[i]) {
-    case '%':
-      if (i < l-1) {
-        switch (s[++i]) {
-        case 'd':
-          q += "dd";
-          continue;
-        case 'm':
-          q += "MM";
-          continue;
-        case 'y':
-          q += "yy";
-          continue;
-        case 'Y':
-          q += "yyyy";
-          continue;
-        case 'H':
-          q += "HH";
-          continue;
-        case 'M':
-          q += "mm";
-          continue;
-        case 'S':
-          q += "ss";
-          continue;
-        case 'A':
-          q += "dddd";
-          continue;
-        case 'a':
-          q += "ddd";
-          continue;
-        case 'B':
-          q += "MMMM";
-          continue;
-        case 'C':
-          q += "yy";
-          continue;
-        case 'D':
-          q += "MM/dd/yyyy";
-          continue;
-        case 'T':
-          q += "hh:mm:ss";
-          continue;
-        case 'F':
-          q += "yyyy-MM-dd";
-          continue;
-        case 'p':
-          q += "AP";
-          continue;
-        default:
-          warning(MYNAME ": omitting unknown strptime conversion \"%%%c\" in \"%s\"\n", s[i], s);
-          break;
-        }
-      }
-      break;
-    default:
-      q += s[i];
-      break;
-    }
-  }
-  return q;
-}
-
-
 /* data parsers */
 
 static QDateTime
 parse_date_and_time(const QString& str)
 {
-  QString timespec = strftime_to_timespec(CSTR(date_time_format));
-  return QDateTime::fromString(QString(str).trimmed(), timespec);
+  return QDateTime::fromString(QString(str).trimmed(), date_time_format);
 }
 
 static uint16_t
diff --git a/gpsbabel-sample.ini b/gpsbabel-sample.ini
index d2feb0217..7e8358420 100644
--- a/gpsbabel-sample.ini
+++ b/gpsbabel-sample.ini
@@ -16,8 +16,8 @@
 
 ;------------------------------------------------------------------
 [ garmin_txt ]
-Date = DD.MM.YYYY
-Time = HH:mm:ss XX
+Date = dd.MM.yyyy
+Time = HH:mm:ss
 Dist = M
 Temp = C
 Prec = 6
diff --git a/reference/format3.txt b/reference/format3.txt
index e647cda7f..cd2f43cc5 100644
--- a/reference/format3.txt
+++ b/reference/format3.txt
@@ -210,7 +210,7 @@ option	gdb	roadbook	Include major turn points (with description) from calculated
 
 file	rwrwrw	garmin_txt	txt	Garmin MapSource - txt (tab delimited)	garmin_txt
 	https://www.gpsbabel.org/WEB_DOC_DIR/fmt_garmin_txt.html
-option	garmin_txt	date	Read/Write date format (i.e. yyyy/mm/dd)	string				https://www.gpsbabel.org/WEB_DOC_DIR/fmt_garmin_txt.html#fmt_garmin_txt_o_date
+option	garmin_txt	date	Read/Write date format (e.g. yyyy/MM/dd)	string				https://www.gpsbabel.org/WEB_DOC_DIR/fmt_garmin_txt.html#fmt_garmin_txt_o_date
 
 option	garmin_txt	datum	GPS datum (def. WGS 84)	string	WGS 84			https://www.gpsbabel.org/WEB_DOC_DIR/fmt_garmin_txt.html#fmt_garmin_txt_o_datum
 
@@ -222,7 +222,7 @@ option	garmin_txt	prec	Precision of coordinates	integer	3			https://www.gpsbabel
 
 option	garmin_txt	temp	Temperature unit [c=Celsius, f=Fahrenheit]	string	c			https://www.gpsbabel.org/WEB_DOC_DIR/fmt_garmin_txt.html#fmt_garmin_txt_o_temp
 
-option	garmin_txt	time	Read/Write time format (i.e. HH:mm:ss xx)	string				https://www.gpsbabel.org/WEB_DOC_DIR/fmt_garmin_txt.html#fmt_garmin_txt_o_time
+option	garmin_txt	time	Read/Write time format (e.g. HH:mm:ss)	string				https://www.gpsbabel.org/WEB_DOC_DIR/fmt_garmin_txt.html#fmt_garmin_txt_o_time
 
 option	garmin_txt	utc	Write timestamps with offset x to UTC time	integer		-23	+23	https://www.gpsbabel.org/WEB_DOC_DIR/fmt_garmin_txt.html#fmt_garmin_txt_o_utc
 
diff --git a/reference/garmincategories.txt b/reference/garmincategories.txt
index b7ec5292c..ccce49a8b 100644
--- a/reference/garmincategories.txt
+++ b/reference/garmincategories.txt
@@ -3,5 +3,5 @@ Datum	WGS 84
 
 Header	Name	Description	Type	Position	Altitude	Depth	Proximity	Temperature	Display Mode	Color	Symbol	Facility	City	State	Country	Date Modified	Link	Categories
 
-Waypoint	Hwy 119	The Diagonal	User Waypoint	N39 58.432183 W105 27.951022					Symbol & Name	Unknown	Flag, Blue					09.03.2013 13:45:12 PM 		Slow food,Category 11
-Waypoint	Hwy 72	The Peak to Peak	User Waypoint	N40 00.238037 W105 29.937744					Symbol & Name	Unknown	Flag, Blue					09.03.2013 13:45:02 PM 		
+Waypoint	Hwy 119	The Diagonal	User Waypoint	N39 58.432183 W105 27.951022					Symbol & Name	Unknown	Flag, Blue					09.03.2013 13:45:12 		Slow food,Category 11
+Waypoint	Hwy 72	The Peak to Peak	User Waypoint	N40 00.238037 W105 29.937744					Symbol & Name	Unknown	Flag, Blue					09.03.2013 13:45:02 		
diff --git a/reference/help.txt b/reference/help.txt
index 8a6f24c5e..fe8c1794e 100644
--- a/reference/help.txt
+++ b/reference/help.txt
@@ -110,13 +110,13 @@ File Types (-i and -o options):
 	  dropwpt               (0/1) Don't create waypoints for non-user points
 	  roadbook              (0/1) Include major turn points (with description) from 
 	garmin_txt            Garmin MapSource - txt (tab delimited)
-	  date                  Read/Write date format (i.e. yyyy/mm/dd)
+	  date                  Read/Write date format (e.g. yyyy/MM/dd)
 	  datum                 GPS datum (def. WGS 84)
 	  dist                  Distance unit [m=metric, s=statute]
 	  grid                  Write position using this grid.
 	  prec                  Precision of coordinates
 	  temp                  Temperature unit [c=Celsius, f=Fahrenheit]
-	  time                  Read/Write time format (i.e. HH:mm:ss xx)
+	  time                  Read/Write time format (e.g. HH:mm:ss)
 	  utc                   Write timestamps with offset x to UTC time
 	garmin_poi            Garmin POI database
 	  snlen                 Max synthesized shortname length
diff --git a/util.cc b/util.cc
index c625e95d4..3d6f776db 100644
--- a/util.cc
+++ b/util.cc
@@ -20,13 +20,13 @@
  */
 
 #include <algorithm>                    // for sort
-#include <cctype>                       // for isspace, isalpha, ispunct, tolower, toupper
+#include <cctype>                       // for isspace, tolower
 #include <cerrno>                       // for errno
 #include <climits>                      // for INT_MAX, INT_MIN
 #include <cmath>                        // for fabs, floor
 #include <cstdio>                       // for size_t, vsnprintf, FILE, fopen, printf, sprintf, stderr, stdin, stdout
 #include <cstdlib>                      // for abs, calloc, free, malloc, realloc
-#include <cstring>                      // for strlen, strcat, strstr, memcpy, strcmp, strcpy, strdup, strchr, strerror
+#include <cstring>                      // for strcmp, strstr, memcpy, strdup, strchr, strerror, strlen
 
 #include <QByteArray>                   // for QByteArray
 #include <QChar>                        // for QChar, operator<=, operator>=
@@ -563,169 +563,6 @@ rot13(const QString& s)
   return r;
 }
 
-/*
- * Convert a human readable date format (i.e. "YYYY/MM/DD") into
- * a format usable for strftime and others
- */
-
-QString
-convert_human_date_format(const char* human_datef)
-{
-  char* result = (char*) xcalloc((2*strlen(human_datef)) + 1, 1);
-  char* cout = result;
-  char prev = '\0';
-  int ylen = 0;
-
-  for (const char* cin = human_datef; *cin; cin++) {
-    char okay = 1;
-
-    if (toupper(*cin) != 'Y') {
-      ylen = 0;
-    }
-    if (isalpha(*cin)) {
-      switch (*cin) {
-      case 'y':
-      case 'Y':
-        if (prev != 'Y') {
-          strcat(cout, "%y");
-          cout += 2;
-          prev = 'Y';
-        }
-        ylen++;
-        if (ylen > 2) {
-          *(cout-1) = 'Y';
-        }
-        break;
-      case 'm':
-      case 'M':
-        if (prev != 'M') {
-          strcat(cout, "%m");
-          cout += 2;
-          prev = 'M';
-        }
-        break;
-      case 'd':
-      case 'D':
-        if (prev != 'D') {
-          strcat(cout, "%d");
-          cout += 2;
-          prev = 'D';
-        }
-        break;
-      default:
-        okay = 0;
-      }
-    } else if (ispunct(*cin)) {
-      *cout++ = *cin;
-      prev = '\0';
-    } else {
-      okay = 0;
-    }
-
-    if (okay == 0) {
-      fatal("Invalid character \"%c\" in date format \"%s\"!\n", *cin, human_datef);
-    }
-  }
-  QString rv(result);
-  xfree(result);
-  return rv;
-}
-
-/*
- * Convert a human readable time format (i.e. "HH:mm:ss") into
- * a format usable for strftime and others
- */
-
-QString
-convert_human_time_format(const char* human_timef)
-{
-  char* result = (char*) xcalloc((2*strlen(human_timef)) + 1, 1);
-  char* cout = result;
-  char prev = '\0';
-
-  for (const char* cin = human_timef; *cin; cin++) {
-    int okay = 1;
-
-    if (isalpha(*cin)) {
-      switch (*cin) {
-      case 'S':
-      case 's':
-        if (prev != 'S') {
-          strcat(cout, "%S");
-          cout += 2;
-          prev = 'S';
-        }
-        break;
-
-      case 'M':
-      case 'm':
-        if (prev != 'M') {
-          strcat(cout, "%M");
-          cout += 2;
-          prev = 'M';
-        }
-        break;
-
-      case 'h':				/* 12-hour-clock */
-        if (prev != 'H') {
-          strcat(cout, "%l");	/* 1 .. 12 */
-          cout += 2;
-          prev = 'H';
-        } else {
-          *(cout-1) = 'I';  /* 01 .. 12 */
-        }
-        break;
-
-      case 'H':				/* 24-hour-clock */
-        if (prev != 'H') {
-          strcat(cout, "%k");
-          cout += 2;
-          prev = 'H';
-        } else {
-          *(cout-1) = 'H';
-        }
-        break;
-
-      case 'x':
-        if (prev != 'X') {
-          strcat(cout, "%P");
-          cout += 2;
-          prev = 'X';
-        } else {
-          *(cout-1) = 'P';
-        }
-        break;
-
-      case 'X':
-        if (prev != 'X') {
-          strcat(cout, "%p");
-          cout += 2;
-          prev = 'X';
-        } else {
-          *(cout-1) = 'p';
-        }
-        break;
-
-      default:
-        okay = 0;
-      }
-    } else if (ispunct(*cin) || isspace(*cin)) {
-      *cout++ = *cin;
-      prev = '\0';
-    } else {
-      okay = 0;
-    }
-
-    if (okay == 0) {
-      fatal("Invalid character \"%c\" in time format \"%s\"!\n", *cin, human_timef);
-    }
-  }
-  QString rv(result);
-  xfree(result);
-  return rv;
-}
-
-
 /*
  * Return a decimal degree pair as
  * DD.DDDDD  DD MM.MMM or DD MM SS.S

From f540d29abc4d2b01269b1787651d7630ab784a84 Mon Sep 17 00:00:00 2001
From: tsteven4 <13596209+tsteven4@users.noreply.github.com>
Date: Wed, 1 Nov 2023 07:55:30 -0600
Subject: [PATCH 09/11] use QDateTime::setOffsetFromUtc(), toOffsetFromUtc()

to implement the garmin_txt utc option.
---
 garmin_txt.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/garmin_txt.cc b/garmin_txt.cc
index fff8694b1..19e79b6b1 100644
--- a/garmin_txt.cc
+++ b/garmin_txt.cc
@@ -382,7 +382,7 @@ print_date_and_time(const QDateTime& dt)
     return;
   }
   if (gtxt_flags.utc) {
-    *fout << dt.toUTC().addSecs(utc_offs).toString(date_time_format);
+    *fout << dt.toOffsetFromUtc(utc_offs).toString(date_time_format);
   } else {
     *fout << dt.toLocalTime().toString(date_time_format);
   }
@@ -736,7 +736,7 @@ static void
 garmin_txt_adjust_time(QDateTime& dt)
 {
   if (gtxt_flags.utc) {
-    dt = dt.toUTC().addSecs(dt.offsetFromUtc() - utc_offs);
+    dt.setOffsetFromUtc(utc_offs);
   }
 }
 

From 36f6c112ce28c5eea8fe6b194d2a519ff10aad73 Mon Sep 17 00:00:00 2001
From: tsteven4 <13596209+tsteven4@users.noreply.github.com>
Date: Wed, 1 Nov 2023 08:56:36 -0600
Subject: [PATCH 10/11] udpate garmin txt date and time option documentation.

---
 xmldoc/formats/options/garmin_txt-date.xml |  8 ++++++--
 xmldoc/formats/options/garmin_txt-time.xml | 10 ++++++++--
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/xmldoc/formats/options/garmin_txt-date.xml b/xmldoc/formats/options/garmin_txt-date.xml
index 188eb225d..dbe78cd2d 100644
--- a/xmldoc/formats/options/garmin_txt-date.xml
+++ b/xmldoc/formats/options/garmin_txt-date.xml
@@ -1,4 +1,8 @@
 <para>
-This option specifies the input and output format for the date.  The format
-is written similarly to those in Windows.  An example format is "YYYY/MM/DD".
+This option specifies the input and output format for the date.
+Examples are
+<simplelist type="vert">
+<member>"yyyy/MM/dd" - four digit year, month with leading zero, day with leading zero.</member>
+<member>"M/d/yy" - month without leading zero, day without leading zero, two digit year.</member>
+</simplelist>
 </para>
diff --git a/xmldoc/formats/options/garmin_txt-time.xml b/xmldoc/formats/options/garmin_txt-time.xml
index 21675249b..0b4e13822 100644
--- a/xmldoc/formats/options/garmin_txt-time.xml
+++ b/xmldoc/formats/options/garmin_txt-time.xml
@@ -1,4 +1,10 @@
 <para>
-This option specifies the input and output format for the time.  The format
-is written similarly to those in Windows.  An example format is "hh:mm:ss xx".
+This option specifies the input and output format for the time.
+Examples are:
+<simplelist type="vert">
+<member>"h:mm:ss AP" - hour without leading zero and range 1-12, AM/PM display.</member>
+<member>"hh:mm:ss AP" - hour with leading zero and range 1-12, AM/PM display.</member>
+<member>"H:mm:ss" - hour without leading zero and range 0-23.</member>
+<member>"HH:mm:ss" - hour with leading zero and range 0-23.</member>
+</simplelist>
 </para>

From 46c40c7de1af61cb18c09ef72a6ba82197bdc0ed Mon Sep 17 00:00:00 2001
From: tsteven4 <13596209+tsteven4@users.noreply.github.com>
Date: Wed, 1 Nov 2023 08:59:01 -0600
Subject: [PATCH 11/11] reduce variable scope to appease cppcheck.

---
 garmin_txt.cc | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/garmin_txt.cc b/garmin_txt.cc
index 19e79b6b1..f1d5fe50d 100644
--- a/garmin_txt.cc
+++ b/garmin_txt.cc
@@ -678,8 +678,6 @@ static void
 track_disp_wpt_cb(const Waypoint* wpt)
 {
   const Waypoint* prev = cur_info->prev_wpt;
-  int delta;
-  double dist;
 
   *fout << "Trackpoint\t";
 
@@ -697,13 +695,13 @@ track_disp_wpt_cb(const Waypoint* wpt)
 
   if (prev != nullptr) {
     *fout << "\t";
-    delta = prev->GetCreationTime().secsTo(wpt->GetCreationTime());
+    int delta = prev->GetCreationTime().secsTo(wpt->GetCreationTime());
     float temp = wpt->temperature_value_or(-999);
     if (temp != -999) {
       print_temperature(temp);
     }
     *fout << "\t";
-    dist = waypt_distance_ex(prev, wpt);
+    double dist = waypt_distance_ex(prev, wpt);
     print_distance(dist, false, true, 0);
     print_duration(delta);
     print_speed(dist, delta);