gst/: Don't return FLOW_UNEXPECTED when a buffer is before the start of the stream (which might happen with large ID3...

Original commit message from CVS:
* gst/apetag/gsttagdemux.c: (gst_tag_demux_trim_buffer),
(gst_tag_demux_read_range):
* gst/id3demux/gstid3demux.c: (gst_id3demux_trim_buffer),
(gst_id3demux_read_range):
Don't return FLOW_UNEXPECTED when a buffer is before
the start of the stream (which might happen with
large ID3v2 tags if the tag reading was done pullrange
based and we then switched to push mode later on).
Fixes regression introduced by commit from June 29th.

3 files changed, 55 insertions, 12 deletions

diff --git a/ChangeLog b/ChangeLog
index 3f18b9e2..a848b7e6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,17 @@
 2006-07-05  Tim-Philipp Müller  <tim at centricular dot net>
 
+	* gst/apetag/gsttagdemux.c: (gst_tag_demux_trim_buffer),
+	(gst_tag_demux_read_range):
+	* gst/id3demux/gstid3demux.c: (gst_id3demux_trim_buffer),
+	(gst_id3demux_read_range):
+	  Don't return FLOW_UNEXPECTED when a buffer is before
+	  the start of the stream (which might happen with
+	  large ID3v2 tags if the tag reading was done pullrange
+	  based and we then switched to push mode later on).
+	  Fixes regression introduced by commit from June 29th.
+
+2006-07-05  Tim-Philipp Müller  <tim at centricular dot net>
+
 	* ext/taglib/gstid3v2mux.cc:
 	  Make UTF-8 the default encoding when writing string
 	  tags (before, our UTF-8 strings would automatically
diff --git a/gst/apetag/gsttagdemux.c b/gst/apetag/gsttagdemux.c
index 2aa23f44..4a18b07c 100644
--- a/gst/apetag/gsttagdemux.c
+++ b/gst/apetag/gsttagdemux.c
@@ -353,6 +353,10 @@ gst_tag_demux_remove_srcpad (GstTagDemux * demux)
   return res;
 };
 
+/* will return FALSE if buffer is beyond end of data; will return TRUE
+ * if buffer was trimmed successfully or didn't need trimming, but may
+ * also return TRUE and set *buf_ref to NULL if the buffer was before
+ * the start of the data */
 static gboolean
 gst_tag_demux_trim_buffer (GstTagDemux * tagdemux, GstBuffer ** buf_ref)
 {
@@ -377,7 +381,7 @@ gst_tag_demux_trim_buffer (GstTagDemux * tagdemux, GstBuffer ** buf_ref)
 
       if (out_offset >= v1tag_offset) {
         GST_DEBUG_OBJECT (tagdemux, "Buffer is past the end of the data");
-        goto no_out_buffer;
+        goto no_out_buffer_end;
       }
 
       if (out_offset + out_size > v1tag_offset) {
@@ -392,7 +396,7 @@ gst_tag_demux_trim_buffer (GstTagDemux * tagdemux, GstBuffer ** buf_ref)
     if (out_offset <= tagdemux->priv->strip_start) {
       if (out_offset + out_size <= tagdemux->priv->strip_start) {
         GST_DEBUG_OBJECT (tagdemux, "Buffer is before the start of the data");
-        goto no_out_buffer;
+        goto no_out_buffer_start;
       }
 
       trim_start = tagdemux->priv->strip_start - out_offset;
@@ -431,10 +435,18 @@ gst_tag_demux_trim_buffer (GstTagDemux * tagdemux, GstBuffer ** buf_ref)
 
   return TRUE;
 
-no_out_buffer:
-  gst_buffer_unref (buf);
-  *buf_ref = NULL;
-  return FALSE;
+no_out_buffer_end:
+  {
+    gst_buffer_unref (buf);
+    *buf_ref = NULL;
+    return FALSE;
+  }
+no_out_buffer_start:
+  {
+    gst_buffer_unref (buf);
+    *buf_ref = NULL;
+    return TRUE;
+  }
 }
 
 static void
@@ -1171,6 +1183,9 @@ gst_tag_demux_read_range (GstTagDemux * demux,
   if (ret == GST_FLOW_OK && *buffer) {
     if (!gst_tag_demux_trim_buffer (demux, buffer))
       goto read_beyond_end;
+
+    /* this should only happen in streaming mode */
+    g_assert (*buffer != NULL);
   }
 
   return ret;
diff --git a/gst/id3demux/gstid3demux.c b/gst/id3demux/gstid3demux.c
index b498639f..5f51a6a2 100644
--- a/gst/id3demux/gstid3demux.c
+++ b/gst/id3demux/gstid3demux.c
@@ -305,6 +305,10 @@ gst_id3demux_remove_srcpad (GstID3Demux * id3demux)
   return res;
 };
 
+/* will return FALSE if buffer is beyond end of data; will return TRUE
+ * if buffer was trimmed successfully or didn't need trimming, but may
+ * also return TRUE and set *buf_ref to NULL if the buffer was before
+ * the start of the data */
 static gboolean
 gst_id3demux_trim_buffer (GstID3Demux * id3demux, GstBuffer ** buf_ref)
 {
@@ -328,7 +332,7 @@ gst_id3demux_trim_buffer (GstID3Demux * id3demux, GstBuffer ** buf_ref)
 
       if (out_offset >= v1tag_offset) {
         GST_DEBUG_OBJECT (id3demux, "Buffer is past the end of the data");
-        goto no_out_buffer;
+        goto no_out_buffer_end;
       }
 
       if (out_offset + out_size > v1tag_offset) {
@@ -343,7 +347,7 @@ gst_id3demux_trim_buffer (GstID3Demux * id3demux, GstBuffer ** buf_ref)
     if (out_offset <= id3demux->strip_start) {
       if (out_offset + out_size <= id3demux->strip_start) {
         GST_DEBUG_OBJECT (id3demux, "Buffer is before the start of the data");
-        goto no_out_buffer;
+        goto no_out_buffer_start;
       }
 
       trim_start = id3demux->strip_start - out_offset;
@@ -381,10 +385,19 @@ gst_id3demux_trim_buffer (GstID3Demux * id3demux, GstBuffer ** buf_ref)
   }
 
   return TRUE;
-no_out_buffer:
-  gst_buffer_unref (buf);
-  *buf_ref = NULL;
-  return FALSE;
+
+no_out_buffer_end:
+  {
+    gst_buffer_unref (buf);
+    *buf_ref = NULL;
+    return FALSE;
+  }
+no_out_buffer_start:
+  {
+    gst_buffer_unref (buf);
+    *buf_ref = NULL;
+    return TRUE;
+  }
 }
 
 static GstFlowReturn
@@ -945,6 +958,9 @@ gst_id3demux_read_range (GstID3Demux * id3demux,
   if (ret == GST_FLOW_OK && *buffer) {
     if (!gst_id3demux_trim_buffer (id3demux, buffer))
       goto read_beyond_end;
+
+    /* this should only happen in streaming mode */
+    g_assert (*buffer != NULL);
   }
 
   return ret;