Fix crashes caused by .editor.cnf files in DOS, add SFN fallback. (#503)

docs/changelog.txt

@@ -48,6 +48,11 @@ USERS
   hacks (DOS) when copying blocks between boards in the editor.
 + Fixed text input bugs caused by a 2.93b change accidentally
   reenabling old deadcode for exiting intake().
++ Fixed crash when saving editor config files/"Set as Default"
+  after the file fails to open for write. If the ".editor.cnf"
+  file fails to save or load, MZX will attempt to save or load a
+  ".cne" file instead. This allows this feature to work in DOS
+  builds when there is no long filename (LFN) support.
 
 DEVELOPERS
 

src/editor/configure.c

@@ -882,28 +882,77 @@ void free_editor_config(void)
   __free_editor_config(&editor_conf_backup);
 }
 
+static size_t editor_config_full_name(char *dest, size_t dest_len,
+ const char *path, size_t path_len)
+{
+  size_t ret = snprintf(dest, dest_len, "%.*s.editor.cnf",
+   (int)path_len - 4, path);
+  dest[dest_len - 1] = '\0';
+  return ret;
+}
+
+static size_t editor_config_dos_name(char *dest, size_t dest_len,
+ const char *path, size_t path_len)
+{
+  size_t ret = snprintf(dest, dest_len, "%.*s.cne",
+   (int)path_len - 4, path);
+  dest[dest_len - 1] = '\0';
+  return ret;
+}
+
+/* Get the existing world file editor config name, if present. It may have
+ * the extension .editor.cnf (usual) or the extension .cne (DOS). */
+size_t get_local_editor_config_name(char *dest, size_t dest_len,
+ const char *mzx_file_path)
+{
+  struct stat file_info;
+  size_t path_len = strlen(mzx_file_path);
+  size_t ret;
+
+  if(path_len < 4)
+    return 0;
+
+  ret = editor_config_full_name(dest, dest_len, mzx_file_path, path_len);
+  if(ret < dest_len &&
+   vstat(dest, &file_info) >= 0 && S_ISREG(file_info.st_mode))
+  {
+    debug("found editor config: %s\n", dest);
+    return ret;
+  }
+
+  ret = editor_config_dos_name(dest, dest_len, mzx_file_path, path_len);
+  if(ret < dest_len &&
+   vstat(dest, &file_info) >= 0 && S_ISREG(file_info.st_mode))
+  {
+    debug("found editor config: %s\n", dest);
+    return ret;
+  }
+
+  return 0;
+}
+
+// TODO: update this function once there's a good config rewriting routine.
 void save_local_editor_config(struct editor_config_info *conf,
  const char *mzx_file_path)
 {
-  int mzx_file_len = strlen(mzx_file_path) - 4;
+  size_t mzx_file_len = strlen(mzx_file_path);
   char config_file_name[MAX_PATH];
 
   const char comment[]   = "\n############################################################";
   const char comment_a[] = "\n#####  Editor generated configuration - do not modify  #####";
   const char comment_b[] = "\n#####        End editor generated configuration        #####";
   const char *value;
-  vfile *vf;
+  vfile *vf = NULL;
+  boolean exists = false;
   int i;
 
-  if(mzx_file_len <= 0)
+  if(mzx_file_len < 4)
     return;
 
-  // Get our filename
-  snprintf(config_file_name, MAX_PATH, "%.*s.editor.cnf",
-   mzx_file_len, mzx_file_path);
-
   // Does it exist?
-  vf = vfopen_unsafe(config_file_name, "rb");
+  if(get_local_editor_config_name(config_file_name, MAX_PATH, mzx_file_path) > 0)
+    vf = vfopen_unsafe(config_file_name, "rb");
+
   if(vf)
   {
     char *a, *b;
@@ -912,6 +961,8 @@ void save_local_editor_config(struct editor_config_info *conf,
     int config_file_size = 0;
     int config_file_size_b = 0;
 
+    exists = true;
+
     config_file_size = vfilelength(vf, true);
     config_file = cmalloc(config_file_size + 1);
 
@@ -952,6 +1003,11 @@ void save_local_editor_config(struct editor_config_info *conf,
     }
 
     vf = vfopen_unsafe(config_file_name, "wb");
+    if(!vf)
+    {
+      warn("failed to rewrite editor config file\n");
+      return;
+    }
 
     if(config_file_size)
       vfwrite(config_file, 1, config_file_size, vf);
@@ -962,7 +1018,29 @@ void save_local_editor_config(struct editor_config_info *conf,
     free(config_file);
   }
 
+  if(!exists)
+  {
+    // Try creating a file with the normal name first. This may fail in DOS.
+    editor_config_full_name(config_file_name, MAX_PATH,
+     mzx_file_path, mzx_file_len);
+  }
+
   vf = vfopen_unsafe(config_file_name, "a");
+  if(!vf)
+  {
+    if(!exists)
+    {
+      editor_config_dos_name(config_file_name, MAX_PATH,
+       mzx_file_path, mzx_file_len);
+      vf = vfopen_unsafe(config_file_name, "a");
+    }
+    if(!vf)
+    {
+      warn("failed to rewrite editor config file\n");
+      return;
+    }
+  }
+  debug("writing editor config: %s\n", config_file_name);
 
   vf_printf(vf, "%s%s%s\n\n", comment, comment_a, comment);
 

src/editor/configure.h

@@ -139,6 +139,8 @@ EDITOR_LIBSPEC void free_editor_config(void);
 EDITOR_LIBSPEC struct editor_config_info *get_editor_config(void);
 void load_editor_config_backup(void);
 
+size_t get_local_editor_config_name(char *dest, size_t dest_len,
+ const char *mzx_file_path);
 void save_local_editor_config(struct editor_config_info *conf,
  const char *mzx_file_path);
 

src/editor/edit.c

@@ -218,9 +218,7 @@ static boolean editor_reload_world(struct editor_context *editor,
 {
   struct world *mzx_world = ((context *)editor)->world;
 
-  int file_name_len = strlen(file) - 4;
   char config_file_name[MAX_PATH];
-  struct stat file_info;
   boolean ignore;
 
   if(!reload_world(mzx_world, file, &ignore))
@@ -230,11 +228,7 @@ static boolean editor_reload_world(struct editor_context *editor,
   load_editor_config_backup();
 
   // Part 2: Now load the new world.editor.cnf.
-
-  snprintf(config_file_name, MAX_PATH, "%.*s.editor.cnf", file_name_len, file);
-  config_file_name[MAX_PATH - 1] = '\0';
-
-  if(vstat(config_file_name, &file_info) >= 0)
+  if(get_local_editor_config_name(config_file_name, MAX_PATH, file) > 0)
     set_config_from_file(GAME_EDITOR_CNF, config_file_name);
 
   edit_menu_show_board_mod(editor->edit_menu);