[evolution] I#1714 - Composer: Prefer HTML over image on LibreOffice data paste

[Milan Crha <mcrha src gnome org>]

commit 8f7ad8b065e59752c7a9468f14009a5f9d2c663e
Author: Milan Crha <mcrha redhat com>
Date:   Thu Dec 2 14:52:57 2021 +0100

    I#1714 - Composer: Prefer HTML over image on LibreOffice data paste
    
    Closes https://gitlab.gnome.org/GNOME/evolution/-/issues/1714

 src/modules/webkit-editor/e-webkit-editor.c | 38 ++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)
---
diff --git a/src/modules/webkit-editor/e-webkit-editor.c b/src/modules/webkit-editor/e-webkit-editor.c
index ec9f122f6b..4312d7f739 100644
--- a/src/modules/webkit-editor/e-webkit-editor.c
+++ b/src/modules/webkit-editor/e-webkit-editor.c
@@ -5009,6 +5009,41 @@ webkit_editor_load_changed_cb (EWebKitEditor *wk_editor,
        e_content_editor_emit_load_finished (E_CONTENT_EDITOR (wk_editor));
 }
 
+static gboolean
+is_libreoffice_content (GdkAtom *targets,
+                       gint n_targets)
+{
+       struct _prefixes {
+               const gchar *prefix;
+               gint len;
+       } prefixes[] = {
+               { "application/x-openoffice", 0 },
+               { "application/x-libreoffice", 0 }
+       };
+       gint ii, jj;
+
+       for (ii = 0; ii < n_targets; ii++) {
+               gchar *name = gdk_atom_name (targets[ii]);
+
+               if (!name)
+                       continue;
+
+               for (jj = 0; jj < G_N_ELEMENTS (prefixes); jj++) {
+                       if (!prefixes[jj].len)
+                               prefixes[jj].len = strlen (prefixes[jj].prefix);
+                       if (g_ascii_strncasecmp (name, prefixes[jj].prefix, prefixes[jj].len) == 0)
+                               break;
+               }
+
+               g_free (name);
+
+               if (jj < G_N_ELEMENTS (prefixes))
+                       break;
+       }
+
+       return ii < n_targets;
+}
+
 static void
 webkit_editor_paste_clipboard_targets_cb (GtkClipboard *clipboard,
                                           GdkAtom *targets,
@@ -5050,7 +5085,8 @@ webkit_editor_paste_clipboard_targets_cb (GtkClipboard *clipboard,
        }
 
        if (wk_editor->priv->html_mode &&
-           gtk_targets_include_image (targets, n_targets, TRUE)) {
+           gtk_targets_include_image (targets, n_targets, TRUE) &&
+           (!content || !*content || !is_libreoffice_content (targets, n_targets))) {
                gchar *uri;
 
                if (!(uri = e_util_save_image_from_clipboard (clipboard)))