be sure the string is properly padded for the field type

mdaus · Nov 14, 2023 · 1075b4e · 1075b4e
1 parent a370468
commit 1075b4e
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Showing 2 changed files with 36 additions and 5 deletions.
diff --git a/modules/c++/nitf/include/nitf/TRE.hpp b/modules/c++/nitf/include/nitf/TRE.hpp
@@ -366,9 +366,6 @@ DECLARE_CLASS(TRE)
      */
     std::string getID() const;
 
-    private:
-    std::string truncate(const std::string& value, size_t maxDigits) const;
-
     mutable nitf_Error error{};
 };
 }

diff --git a/modules/c++/nitf/source/TRE.cpp b/modules/c++/nitf/source/TRE.cpp
@@ -165,7 +165,7 @@ static bool endsWith(const std::string& s, const std::string& match) noexcept
     return sLen >= mLen;
 }
 
-std::string TRE::truncate(const std::string& value, size_t maxDigits) const 
+static std::string truncate(const std::string& value, size_t maxDigits)
 {
     const size_t decimalIndex = value.find('.');
     if (decimalIndex == std::string::npos)
@@ -184,6 +184,40 @@ std::string TRE::truncate(const std::string& value, size_t maxDigits) const
     }
     return value;
 }
+static std::string truncate(const nitf_Field& field, const std::string& value)
+{
+    auto retval = truncate(value, field.length);
+
+    // From Field.h
+    if (field.type == NITF_BCS_A)
+    {
+        // is BCS-A data, it is space-filled, right-aligned.
+        while (retval.length() < field.length)
+        {
+            // copyAndFillSpaces() in Field.c "Spaces are added to the right" 
+            retval += " ";
+        }
+    }
+    else if (field.type == NITF_BCS_N)
+    {
+        const auto decimalIndex = retval.find('.');
+
+        // If it is BCS-N, we expect zero-filled, left-aligned.
+        while (retval.length() < field.length)
+        {
+            if (decimalIndex == std::string::npos)
+            {
+                retval = "0" + retval;
+            }
+            else
+            {
+                retval += "0";
+            }
+        }
+    }
+
+    return retval;
+}
 
 void TRE::setFieldValue(const std::string& key, const void* data, size_t dataLength, bool forceUpdate)
 {
@@ -207,7 +241,7 @@ void TRE::setFieldValue(const nitf_Field& field, const std::string& key, const s
     else
     {
         // call truncate() first
-        const auto s = truncate(data, field.length);
+        const auto s = truncate(field, data);
         setFieldValue(key, s.c_str(), s.size(), forceUpdate);
     }
 }