[gtksourceview/wip/completion-fix] Completion: make the code more robust wrt contexts

[Sébastien Wilmet <swilmet src gnome org>]

commit 9fe756c699c85779868a9377b01a8546ba720a46
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sat Oct 11 15:53:07 2014 +0200

    Completion: make the code more robust wrt contexts
    
    Before calling a CompletionProvider function, be sure the context is
    still valid. A CompletionProvider should also make the verification, but
    since the verification was not possible before, old code can crash
    without this commit.

 gtksourceview/gtksourcecompletion.c |   35 ++++++++++++++++++++++++++++++-----
 1 files changed, 30 insertions(+), 5 deletions(-)
---
diff --git a/gtksourceview/gtksourcecompletion.c b/gtksourceview/gtksourcecompletion.c
index 8f1e435..40b1619 100644
--- a/gtksourceview/gtksourcecompletion.c
+++ b/gtksourceview/gtksourcecompletion.c
@@ -321,9 +321,15 @@ static GList *
 select_providers (GList                      *providers,
                   GtkSourceCompletionContext *context)
 {
+       GtkTextIter context_iter;
        GList *selection = NULL;
        GList *l;
 
+       if (!gtk_source_completion_context_get_iter (context, &context_iter))
+       {
+               return NULL;
+       }
+
        for (l = providers; l != NULL; l = l->next)
        {
                GtkSourceCompletionProvider *provider = l->data;
@@ -473,7 +479,14 @@ update_window_position (GtkSourceCompletion *completion)
 
        if (get_selected_proposal (completion, &provider, &proposal))
        {
-               if (gtk_source_completion_provider_get_start_iter (provider,
+               GtkTextIter context_iter;
+               gboolean valid_context;
+
+               valid_context = gtk_source_completion_context_get_iter (completion->priv->context,
+                                                                       &context_iter);
+
+               if (valid_context &&
+                   gtk_source_completion_provider_get_start_iter (provider,
                                                                   completion->priv->context,
                                                                   proposal,
                                                                   &iter))
@@ -666,6 +679,8 @@ gtk_source_completion_activate_proposal (GtkSourceCompletion *completion)
        GtkSourceCompletionProvider *provider = NULL;
        GtkSourceCompletionProposal *proposal = NULL;
        GtkTextIter insert_iter;
+       GtkTextIter context_iter;
+       gboolean valid_context;
        gboolean activated;
 
        if (completion->priv->view == NULL)
@@ -684,7 +699,10 @@ gtk_source_completion_activate_proposal (GtkSourceCompletion *completion)
 
        activated = gtk_source_completion_provider_activate_proposal (provider, proposal, &insert_iter);
 
-       if (!activated)
+       valid_context = gtk_source_completion_context_get_iter (completion->priv->context,
+                                                               &context_iter);
+
+       if (!activated && valid_context)
        {
                GtkTextIter start_iter;
                gchar *text = gtk_source_completion_proposal_get_text (proposal);
@@ -1356,6 +1374,8 @@ update_completion (GtkSourceCompletion        *completion,
                    GtkSourceCompletionContext *context)
 {
        GList *item;
+       GtkTextIter context_iter;
+       gboolean valid_context;
 
        /* Copy the parameters, because they can be freed by reset_completion(). */
        GList *providers_copy = g_list_copy (providers);
@@ -1374,10 +1394,15 @@ update_completion (GtkSourceCompletion        *completion,
 
        replace_model (completion);
 
-       for (item = providers_copy; item != NULL; item = g_list_next (item))
+       valid_context = gtk_source_completion_context_get_iter (context_copy, &context_iter);
+
+       if (valid_context)
        {
-               GtkSourceCompletionProvider *provider = item->data;
-               gtk_source_completion_provider_populate (provider, context_copy);
+               for (item = providers_copy; item != NULL; item = g_list_next (item))
+               {
+                       GtkSourceCompletionProvider *provider = item->data;
+                       gtk_source_completion_provider_populate (provider, context_copy);
+               }
        }
 
        g_list_free (providers_copy);