properly handle long filenames of preloade files

src/main.c

@@ -546,6 +546,69 @@ CT_ASSERT(sizeof(T_Components)==3);
 // when sizeof(T_Palette) is not 768.
 CT_ASSERT(sizeof(T_Palette)==768);
 
+/**
+ * Convert a file name to unicode characters
+ *
+ * @param filename_unicode the output buffer of MAX_PATH_CHARACTERS wide characters
+ * @param filename the input file name
+ * @param directory the input file directory
+ * @return 0 if no conversion has taken place.
+ * @return 1 if the unicode filename has been retrieved
+ */
+static int Get_Unicode_Filename(word * filename_unicode, const char * filename, const char * directory)
+{
+#if defined(WIN32)
+  int i = 0, j = 0;
+  WCHAR shortPath[MAX_PATH_CHARACTERS];
+  WCHAR longPath[MAX_PATH_CHARACTERS];
+
+  // copy the full path to a wide character buffer :
+  while (directory[0] != '\0')
+    shortPath[i++] = *directory++;
+  if (i > 0 && shortPath[i-1] != '\\')   // add path separator only if it is missing
+    shortPath[i++] = '\\';
+  while (filename[0] != '\0')
+    shortPath[i++] = *filename++;
+  shortPath[i++] = 0;
+  if (GetLongPathNameW(shortPath, longPath, MAX_PATH_CHARACTERS) == 0)
+    return 0;
+  i = 0;
+  while (longPath[j] != 0)
+  {
+    if (longPath[j] == '\\')
+      i = 0;
+    else
+      filename_unicode[i++] = longPath[j];
+    j++;
+  }
+  filename_unicode[i++] = 0;
+  return 1;
+#elif defined(ENABLE_FILENAMES_ICONV)
+  char * input = filename;
+  size_t inbytesleft = strlen(filename);
+  char * output = (char *)filename_unicode;
+  size_t outbytesleft = (MAX_PATH_CHARACTERS - 1) * 2;
+  (void)directory;  // unused
+  if (cd_utf16 != (iconv_t)-1)
+  {
+    size_t r = iconv(cd_utf16, &input, &inbytesleft, &output, &outbytesleft);
+    if (r != (size_t)-1)
+    {
+      output[0] = '\0';
+      output[1] = '\0';
+      return 1;
+    }
+  }
+  return 0;
+#else
+  (void)filename_unicode;
+  (void)filename;
+  (void)directory;
+  // not implemented
+  return 0;
+#endif
+}
+
 // ------------------------ Initialiser le programme -------------------------
 // Returns 0 on fail
 int Init_program(int argc,char * argv[])
@@ -558,12 +621,12 @@ int Init_program(int argc,char * argv[])
   int file_in_command_line;
   T_Gradient_array initial_gradients;
   static char main_filename [MAX_PATH_CHARACTERS];
-#ifdef ENABLE_FILENAMES_ICONV
-  static word main_filename_unicode[MAX_PATH_CHARACTERS];
-#endif
   static char main_directory[MAX_PATH_CHARACTERS];
   static char spare_filename [MAX_PATH_CHARACTERS];
   static char spare_directory[MAX_PATH_CHARACTERS];
+#if defined(ENABLE_FILENAMES_ICONV) || defined(WIN32)
+  static word filename_unicode[MAX_PATH_CHARACTERS];
+#endif
 
   #if defined(__MINT__)
   printf("===============================\n");
@@ -1022,6 +1085,8 @@ int Init_program(int argc,char * argv[])
         case 2:
           // Load this file
           Init_context_layered_image(&context, spare_filename, spare_directory);
+          if (Get_Unicode_Filename(filename_unicode, spare_filename, spare_directory))
+            context.File_name_unicode = filename_unicode;
           Load_image(&context);
           Destroy_context(&context);
           Redraw_layered_image();
@@ -1031,24 +1096,8 @@ int Init_program(int argc,char * argv[])
           // no break ! proceed with the other file now
         case 1:
           Init_context_layered_image(&context, main_filename, main_directory);
-#ifdef ENABLE_FILENAMES_ICONV
+          if (Get_Unicode_Filename(filename_unicode, main_filename, main_directory))
-          {
+            context.File_name_unicode = filename_unicode;
-            char * input = main_filename;
-            size_t inbytesleft = strlen(main_filename);
-            char * output = (char *)main_filename_unicode;
-            size_t outbytesleft = sizeof(main_filename_unicode) - 2;
-            if (cd_utf16 != (iconv_t)-1)
-            {
-              size_t r = iconv(cd_utf16, &input, &inbytesleft, &output, &outbytesleft);
-              if (r != (size_t)-1)
-              {
-                output[0] = '\0';
-                output[1] = '\0';
-                context.File_name_unicode = main_filename_unicode;
-              }
-            }
-          }
-#endif
           Load_image(&context);
           Destroy_context(&context);
           Redraw_layered_image();