[gtksourceview/wip/loader-saver] Make sure text passed to insert_text is null terminated

[Sébastien Wilmet <swilmet src gnome org>]

commit d77e9f0fa07fe0277225e72097bcbcc1626db0b3
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Tue Jul 1 14:43:25 2014 +0200

    Make sure text passed to insert_text is null terminated
    
    Based on Jesse's commit d50108e57935871125cb42f275ebc2f096448452 in
    gedit.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=726390

 gtksourceview/gtksourcebufferoutputstream.c |   63 ++++++++++++++++++++++----
 1 files changed, 53 insertions(+), 10 deletions(-)
---
diff --git a/gtksourceview/gtksourcebufferoutputstream.c b/gtksourceview/gtksourcebufferoutputstream.c
index 235d7e3..6511d32 100644
--- a/gtksourceview/gtksourcebufferoutputstream.c
+++ b/gtksourceview/gtksourcebufferoutputstream.c
@@ -593,12 +593,14 @@ insert_fallback (GtkSourceBufferOutputStream *stream,
 
 static void
 validate_and_insert (GtkSourceBufferOutputStream *stream,
-                    const gchar                 *buffer,
-                    gsize                        count)
+                    gchar                       *buffer,
+                    gsize                        count,
+                    gboolean                     owned)
 {
        GtkTextBuffer *text_buffer;
        GtkTextIter *iter;
        gsize len;
+       gchar *free_text = NULL;
 
        if (stream->priv->source_buffer == NULL)
        {
@@ -632,8 +634,9 @@ validate_and_insert (GtkSourceBufferOutputStream *stream,
 
                        if (ptr && *ptr == '\r' && ptr - buffer == len - 1)
                        {
-                               stream->priv->buffer = g_new (gchar, 1);
+                               stream->priv->buffer = g_new (gchar, 2);
                                stream->priv->buffer[0] = '\r';
+                               stream->priv->buffer[1] = '\0';
                                stream->priv->buflen = 1;
 
                                /* Decrease also the len so in the check
@@ -646,10 +649,42 @@ validate_and_insert (GtkSourceBufferOutputStream *stream,
                /* if we've got any valid char we must tag the invalid chars */
                if (nvalid > 0)
                {
+                       gchar orig_non_null = '\0';
+
                        apply_error_tag (stream);
-               }
 
-               gtk_text_buffer_insert (text_buffer, iter, buffer, nvalid);
+                       if (nvalid != len && buffer[nvalid] != '\0')
+                       {
+                               /* make sure the buffer is always properly null
+                                * terminated. This is needed, at least for now,
+                                * to avoid issues with pygobject marshalling of
+                                * the insert-text signal of gtktextbuffer
+                                *
+                                * https://bugzilla.gnome.org/show_bug.cgi?id=726689
+                                */
+                               if (!owned)
+                               {
+                                       /* forced to make a copy */
+                                       free_text = g_new (gchar, len + 1);
+                                       memcpy (free_text, buffer, len);
+                                       free_text[len] = '\0';
+
+                                       buffer = free_text;
+                                       owned = TRUE;
+                               }
+
+                               orig_non_null = buffer[nvalid];
+                               buffer[nvalid] = '\0';
+                       }
+
+                       gtk_text_buffer_insert (text_buffer, iter, buffer, nvalid);
+
+                       if (orig_non_null != '\0')
+                       {
+                               /* restore null terminated replaced byte */
+                               buffer[nvalid] = orig_non_null;
+                       }
+               }
 
                /* If we inserted all return */
                if (nvalid == len)
@@ -679,6 +714,8 @@ validate_and_insert (GtkSourceBufferOutputStream *stream,
                ++buffer;
                --len;
        }
+
+       g_free (free_text);
 }
 
 static void
@@ -749,7 +786,9 @@ convert_text (GtkSourceBufferOutputStream  *stream,
        outbuf_size = (inbuf_len > 0) ? inbuf_len : 100;
 
        out_left = outbuf_size;
-       out = dest = g_malloc (outbuf_size);
+
+       /* keep room for null termination */
+       out = dest = g_malloc (sizeof (gchar) * (outbuf_size + 1));
 
        done = FALSE;
        have_error = FALSE;
@@ -783,7 +822,10 @@ convert_text (GtkSourceBufferOutputStream  *stream,
                                                gsize used = out - dest;
 
                                                outbuf_size *= 2;
-                                               dest = g_realloc (dest, outbuf_size);
+
+                                               /* make sure to allocate room for
+                                                  terminating null byte */
+                                               dest = g_realloc (dest, outbuf_size + 1);
 
                                                out = dest + used;
                                                out_left = outbuf_size - used;
@@ -820,9 +862,10 @@ convert_text (GtkSourceBufferOutputStream  *stream,
                return FALSE;
        }
 
-       *outbuf = dest;
        *outbuf_len = out - dest;
+       dest[*outbuf_len] = '\0';
 
+       *outbuf = dest;
        return TRUE;
 }
 
@@ -1000,7 +1043,7 @@ gtk_source_buffer_output_stream_write (GOutputStream  *stream,
                len = outbuf_len;
        }
 
-       validate_and_insert (ostream, text, len);
+       validate_and_insert (ostream, text, len, freetext);
 
        if (freetext)
        {
@@ -1033,7 +1076,7 @@ gtk_source_buffer_output_stream_flush (GOutputStream  *stream,
 
                if (convert_text (ostream, NULL, 0, &outbuf, &outbuf_len, error))
                {
-                       validate_and_insert (ostream, outbuf, outbuf_len);
+                       validate_and_insert (ostream, outbuf, outbuf_len, TRUE);
                        g_free (outbuf);
                }
                else