docs/design/part-seeking.txt: Some small update.

Original commit message from CVS:
* docs/design/part-seeking.txt:
Some small update.
* gst/gstsegment.c: (gst_segment_set_seek):
Revert old bogus change that should make seeking work again.

ChangeLog

@@ -1,3 +1,11 @@
+2007-02-13  Wim Taymans,,,  <wim@fluendo.com>
+
+	* docs/design/part-seeking.txt:
+	Some small update.
+
+	* gst/gstsegment.c: (gst_segment_set_seek):
+	Revert old bogus change that should make seeking work again.
+
 2007-02-13  Stefan Kost  <ensonic@users.sf.net>
 
 	* docs/random/ensonic/dynlink.txt:

docs/design/part-seeking.txt

@@ -30,7 +30,7 @@ earliest element in the pipeline, typically a demuxer. After receiving
 the message, the application can reconnect the pipeline or issue other
 seek events in the pipeline. Since the message is posted as early as
 possible in the pipeline, the application has some time to issue a new
-seek to make the transition seemless. Typically the allowed delay is
+seek to make the transition seamless. Typically the allowed delay is
 defined by the buffer sizes of the sinks as well as the size of any 
 queues in the pipeline.
 

gst/gstsegment.c

@@ -230,7 +230,7 @@ gst_segment_set_last_stop (GstSegment * segment, GstFormat format,
  * @start: the seek start value
  * @stop_type: the seek method
  * @stop: the seek stop value
- * @update: boolean holding whether start or stop were updated.
+ * @update: boolean holding whether last_stop was updated.
  *
  * Update the segment structure with the field values of a seek event (see
  * gst_event_new_seek()).
@@ -255,6 +255,10 @@ gst_segment_set_last_stop (GstSegment * segment, GstFormat format,
  * The applied rate of the segment will be set to 1.0 by default.
  * If the caller can apply a rate change, it should update @segment
  * rate and applied_rate after calling this function.
+ *
+ * @update will be set to TRUE if a seek should be performed to the segment 
+ * last_stop field. This field can be FALSE if, for example, only the @rate
+ * has been changed but not the playback position.
  */
 void
 gst_segment_set_seek (GstSegment * segment, gdouble rate,
@@ -263,6 +267,7 @@ gst_segment_set_seek (GstSegment * segment, gdouble rate,
     GstSeekType stop_type, gint64 stop, gboolean * update)
 {
   gboolean update_stop, update_start;
+  gint64 last_stop;
 
   g_return_if_fail (rate != 0.0);
   g_return_if_fail (segment != NULL);
@@ -272,7 +277,7 @@ gst_segment_set_seek (GstSegment * segment, gdouble rate,
   else
     g_return_if_fail (segment->format == format);
 
-  update_stop = update_start = TRUE;
+  update_start = update_stop = TRUE;
 
   /* start is never invalid */
   switch (start_type) {
@@ -285,20 +290,14 @@ gst_segment_set_seek (GstSegment * segment, gdouble rate,
       /* start holds desired position, map -1 to the start */
       if (start == -1)
         start = 0;
-      if (start == segment->start)
-        update_start = FALSE;
       break;
     case GST_SEEK_TYPE_CUR:
       /* add start to currently configure segment */
-      if (start == 0)
-        update_start = FALSE;
       start = segment->start + start;
       break;
     case GST_SEEK_TYPE_END:
       if (segment->duration != -1) {
         /* add start to total length */
-        if (start == 0)
-          update_start = FALSE;
         start = segment->duration + start;
       } else {
         /* no update if duration unknown */
@@ -323,21 +322,15 @@ gst_segment_set_seek (GstSegment * segment, gdouble rate,
       /* stop holds required value */
       break;
     case GST_SEEK_TYPE_CUR:
-      if (segment->stop != -1) {
+      if (segment->stop != -1)
-        if (stop == 0)
-          update_stop = FALSE;
         stop = segment->stop + stop;
-      } else {
+      else
         stop = -1;
-        update_stop = FALSE;
-      }
       break;
     case GST_SEEK_TYPE_END:
-      if (segment->duration != -1) {
+      if (segment->duration != -1)
-        if (stop == 0)
-          update_stop = FALSE;
         stop = segment->duration + stop;
-      } else {
+      else {
         stop = segment->stop;
         update_stop = FALSE;
       }
@@ -361,24 +354,30 @@ gst_segment_set_seek (GstSegment * segment, gdouble rate,
   segment->applied_rate = 1.0;
   segment->flags = flags;
   segment->start = start;
+  last_stop = segment->last_stop;
   if (update_start && rate > 0.0) {
-    segment->last_stop = start;
+    last_stop = start;
   }
   if (update_stop && rate < 0.0) {
     if (stop != -1)
-      segment->last_stop = stop;
+      last_stop = stop;
     else {
       if (segment->duration != -1)
-        segment->last_stop = segment->duration;
+        last_stop = segment->duration;
       else
-        segment->last_stop = 0;
+        last_stop = 0;
     }
   }
+  /* set update arg to reflect update of last_stop */
+  if (update)
+    *update = last_stop != segment->last_stop;
+
+  /* update new position */
+  if (last_stop != segment->last_stop)
+    segment->last_stop = last_stop;
+
   segment->time = start;
   segment->stop = stop;
-
-  if (update)
-    *update = update_start || update_stop;
 }
 
 /**