[gtksourceview] Fix a bug with gtk_source_search_context_get_occurrence_position()

[Sébastien Wilmet <swilmet src gnome org>]

commit 6498300dd2899633911da60aa0e77dd60a8be981
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Tue Aug 27 19:41:26 2013 +0200

    Fix a bug with gtk_source_search_context_get_occurrence_position()

 gtksourceview/gtksourcesearchcontext.c |   43 +++++++++++++++++++++++++------
 1 files changed, 34 insertions(+), 9 deletions(-)
---
diff --git a/gtksourceview/gtksourcesearchcontext.c b/gtksourceview/gtksourcesearchcontext.c
index 1a392df..4b7d118 100644
--- a/gtksourceview/gtksourcesearchcontext.c
+++ b/gtksourceview/gtksourcesearchcontext.c
@@ -1371,8 +1371,9 @@ adjust_subregion (GtkSourceSearchContext *search,
        });
 }
 
-/* Do not take into account the scan_region. Search just with
- * forward_to_tag_toggle(), and checks that it is not an old match.
+/* Do not take into account the scan_region. Take the result with a grain of
+ * salt. You should verify before or after calling this function that the
+ * region has been scanned, to be sure that the returned occurrence is correct.
  */
 static gboolean
 smart_forward_search_without_scanning (GtkSourceSearchContext *search,
@@ -3067,11 +3068,12 @@ gtk_source_search_context_get_occurrences_count (GtkSourceSearchContext *search)
  * @match_end: the end of the occurrence.
  *
  * Gets the position of a search occurrence. If the buffer is not already fully
- * scanned, the position may be unknown, and -1 is returned. Therefore you
- * should call this function when you know that the buffer is fully scanned.
+ * scanned, the position may be unknown, and -1 is returned. If 0 is returned,
+ * it means that this part of the buffer has already been scanned, and that
+ * @match_start and @match_end don't delimit an occurrence.
  *
  * Returns: the position of the search occurrence. The first occurrence has the
- * position 1 (not 0). Returns 0 if @match_start and @match_end doesn't delimit
+ * position 1 (not 0). Returns 0 if @match_start and @match_end don't delimit
  * an occurrence. Returns -1 if the position is not yet known.
  *
  * Since: 3.10
@@ -3086,6 +3088,8 @@ gtk_source_search_context_get_occurrence_position (GtkSourceSearchContext *searc
        GtkTextIter iter;
        gboolean found;
        gint position = 0;
+       GtkTextRegion *region;
+       gboolean empty;
 
        g_return_val_if_fail (GTK_SOURCE_IS_SEARCH_CONTEXT (search), -1);
        g_return_val_if_fail (match_start != NULL, -1);
@@ -3096,6 +3100,27 @@ gtk_source_search_context_get_occurrence_position (GtkSourceSearchContext *searc
                return -1;
        }
 
+       /* Verify that the [match_start; match_end] region has been scanned. */
+
+       if (search->priv->scan_region != NULL)
+       {
+               region = gtk_text_region_intersect (search->priv->scan_region,
+                                                   match_start,
+                                                   match_end);
+
+               empty = is_text_region_empty (region);
+
+               if (region != NULL)
+               {
+                       gtk_text_region_destroy (region, TRUE);
+               }
+
+               if (!empty)
+               {
+                       return -1;
+               }
+       }
+
        /* Verify that the occurrence is correct. */
 
        found = smart_forward_search_without_scanning (search,
@@ -3119,11 +3144,11 @@ gtk_source_search_context_get_occurrence_position (GtkSourceSearchContext *searc
 
        if (search->priv->scan_region != NULL)
        {
-               GtkTextRegion *region = gtk_text_region_intersect (search->priv->scan_region,
-                                                                  &iter,
-                                                                  match_end);
+               region = gtk_text_region_intersect (search->priv->scan_region,
+                                                   &iter,
+                                                   match_end);
 
-               gboolean empty = is_text_region_empty (region);
+               empty = is_text_region_empty (region);
 
                if (region != NULL)
                {