[gimp/gimp-2-10] plug-ins: In metadata-editor always read iptc equivalent values of xmp tags.

[Jacob Boerema <jboerema src gnome org>]

commit 1055016eb568f9162faa3e6bc5eb51f38accf3ae
Author: Jacob Boerema <jgboerema gmail com>
Date:   Wed Nov 18 18:54:43 2020 -0500

    plug-ins: In metadata-editor always read iptc equivalent values of xmp tags.
    
    Iptc equivalent tags of Xmp tags were only read if the Xmp tag had no value
    which doesn't make sense since there is no guarantee that they are the same.
    
    We changed this to always read the Iptc tags too and if the value differs
    from the Xmp tag we add both values. That way the user can decide
    which values are relevant.
    
    (cherry picked from commit 7cce45b3773add108eefda8b4ed8204baaef0647)

 plug-ins/metadata/metadata-editor.c | 114 ++++++++++++++++++++++--------------
 1 file changed, 69 insertions(+), 45 deletions(-)
---
diff --git a/plug-ins/metadata/metadata-editor.c b/plug-ins/metadata/metadata-editor.c
index 84982df512..66b8fa9944 100644
--- a/plug-ins/metadata/metadata-editor.c
+++ b/plug-ins/metadata/metadata-editor.c
@@ -1878,95 +1878,119 @@ metadata_dialog_editor_set_metadata (GExiv2Metadata *metadata,
   for (i = 0; i < numele; i++)
     {
       GtkWidget *widget;
+      gint       index;
 
       widget = builder_get_widget (builder, default_metadata_tags[i].tag);
 
       value = gexiv2_metadata_get_tag_interpreted_string (metadata,
                                                           default_metadata_tags[i].tag);
 
-      if (! value || value[0] == '\0')
+      if (value)
         {
-          gint index;
+          gchar *value_utf8 = clean_xmp_string (value);
 
-          if (value)
-            g_free (value);
+          g_free (value);
 
-          index = default_metadata_tags[i].other_tag_index;
-          if (index > -1)
+          if (value_utf8 && value_utf8[0] != '\0')
             {
-              gchar **values;
-
-              /* These are all IPTC tags some of which can appear multiple times so
-               * we will use get_tag_multiple. Also IPTC most commonly uses UTF-8
-               * not current locale so get_tag_interpreted was wrong anyway.
-               * FIXME For now lets interpret as UTF-8 and in the future read
-               * and interpret based on the CharacterSet tag.
-               */
-              values = gexiv2_metadata_get_tag_multiple (metadata,
-                                                         equivalent_metadata_tags[index].tag);
-
-              if (values)
-                {
-                  gint     i;
-                  GString *str = NULL;
+              value = g_strdup (value_utf8);
+            }
+          else
+            {
+              value = NULL;
+            }
+
+          g_free (value_utf8);
+        }
 
-                  for (i = 0; values[i] != NULL; i++)
+      index = default_metadata_tags[i].other_tag_index;
+      if (index > -1)
+        {
+          gchar **values;
+
+          /* These are all IPTC tags some of which can appear multiple times so
+            * we will use get_tag_multiple. Also IPTC most commonly uses UTF-8
+            * not current locale so get_tag_interpreted was wrong anyway.
+            * FIXME For now lets interpret as UTF-8 and in the future read
+            * and interpret based on the CharacterSet tag.
+            */
+          values = gexiv2_metadata_get_tag_multiple (metadata,
+                                                     equivalent_metadata_tags[index].tag);
+
+          if (values)
+            {
+              gint     i;
+              GString *str = NULL;
+
+              for (i = 0; values[i] != NULL; i++)
+                {
+                  if (values[i][0] != '\0')
                     {
-                      if (values[i][0] != '\0')
+                      if (! str)
                         {
-                          if (! str)
+                          str = g_string_new (values[i]);
+                        }
+                      else
+                        {
+                          if (! strcmp ("multi", equivalent_metadata_tags[index].mode))
                             {
-                              str = g_string_new (values[i]);
+                              g_string_append (str, "\n");
                             }
                           else
                             {
-                              if (! strcmp ("multi", equivalent_metadata_tags[index].mode))
-                                {
-                                  g_string_append (str, "\n");
-                                }
-                              else
-                                {
-                                  g_string_append (str, ", ");
-                                }
-                              g_string_append (str, values[i]);
+                              g_string_append (str, ", ");
                             }
+                          g_string_append (str, values[i]);
                         }
                     }
+                }
 
-                  if (str)
+              if (str)
+                {
+                  /* If we got values from both Xmp and Iptc then compare those
+                    * values and if they are different concatenate them. Usually they
+                    * should be the same in which case we won't duplicate the string.
+                    */
+                  if (value && strcmp (value, str->str))
                     {
-                      value = g_string_free (str, FALSE);
+                      if (! strcmp ("multi", equivalent_metadata_tags[index].mode))
+                        {
+                          g_string_prepend (str, "\n");
+                        }
+                      else
+                        {
+                          g_string_prepend (str, ", ");
+                        }
+                      g_string_prepend (str, value);
+                      g_free (value);
                     }
+                  value = g_string_free (str, FALSE);
                 }
             }
         }
 
       if (value)
         {
-          gchar *value_utf;
-
-          value_utf = clean_xmp_string (value);
-
           if (! strcmp ("Exif.GPSInfo.GPSAltitude",
                         default_metadata_tags[i].tag) &&
-              value_utf)
+              value)
             {
               gchar *new_value_clean[2];
 
-              new_value_clean[0] = strtok (value_utf, " ");
-              strcpy (value_utf, new_value_clean[0]);
+              new_value_clean[0] = strtok (value, " ");
+              strcpy (value, new_value_clean[0]);
             }
 
           if (! strcmp ("single", default_metadata_tags[i].mode))
             {
-              gtk_entry_set_text (GTK_ENTRY (widget), value_utf);
+              gtk_entry_set_text (GTK_ENTRY (widget), value);
             }
           else if (! strcmp ("multi", default_metadata_tags[i].mode))
             {
               GtkTextBuffer *buffer;
 
               buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (widget));
-              gtk_text_buffer_set_text (buffer, value_utf, -1);
+              gtk_text_buffer_set_text (buffer, value, -1);
             }
           else if (!strcmp ("list", default_metadata_tags[i].mode))
             {