From a5ee20db3f933314b48f8ef5beff1eb9548f8cb0 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wim.taymans@collabora.co.uk>
Date: Tue, 12 Jul 2011 12:00:58 +0200
Subject: [PATCH] buffer: fix _resize some more

Add more debug.
Alow resize to 0 bytes.
Do clipping correctly.
Add more unit tests. Also add a failing test: when we resize to 0 and then
try to resize back to the original size it fails because the memory was
removed.
---
 gst/gstbuffer.c             | 12 +++++++-----
 tests/check/gst/gstbuffer.c | 18 ++++++++++++++++++
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/gst/gstbuffer.c b/gst/gstbuffer.c
index 2bcfe73..2ce0540 100644
--- a/gst/gstbuffer.c
+++ b/gst/gstbuffer.c
@@ -820,13 +820,14 @@ gst_buffer_resize (GstBuffer * buffer, gssize offset, gsize size)
   gsize bsize, bufsize, bufoffs, bufmax;
   GstMemory *mem;
 
-  GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSIZE_FORMAT,
-      buffer, offset, size);
-
   g_return_if_fail (gst_buffer_is_writable (buffer));
 
   bufsize = gst_buffer_get_sizes (buffer, &bufoffs, &bufmax);
 
+  GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSIZE_FORMAT
+      " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%" G_GSIZE_FORMAT,
+      buffer, offset, size, bufsize, bufoffs, bufmax);
+
   /* we can't go back further than the current offset or past the end of the
    * buffer */
   g_return_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
@@ -840,12 +841,13 @@ gst_buffer_resize (GstBuffer * buffer, gssize offset, gsize size)
   len = GST_BUFFER_MEM_LEN (buffer);
 
   /* copy and trim */
-  for (di = si = 0; si < len && size > 0; si++) {
+  for (di = si = 0; si < len; si++) {
     mem = GST_BUFFER_MEM_PTR (buffer, si);
     bsize = gst_memory_get_sizes (mem, NULL, NULL);
 
     if ((gssize) bsize <= offset) {
       /* remove buffer */
+      GST_CAT_LOG (GST_CAT_BUFFER, "remove memory %p", mem);
       gst_memory_unref (mem);
       offset -= bsize;
     } else {
@@ -857,7 +859,7 @@ gst_buffer_resize (GstBuffer * buffer, gssize offset, gsize size)
       else
         left = MIN (bsize - offset, size);
 
-      if (left) {
+      if (offset != 0 || left != bsize) {
         /* we need to clip something */
         if (GST_MEMORY_IS_WRITABLE (mem)) {
           gst_memory_resize (mem, offset, left);
diff --git a/tests/check/gst/gstbuffer.c b/tests/check/gst/gstbuffer.c
index 22cbef7..d900399 100644
--- a/tests/check/gst/gstbuffer.c
+++ b/tests/check/gst/gstbuffer.c
@@ -515,6 +515,24 @@ GST_START_TEST (test_resize)
   fail_unless (offset == 0);
   fail_unless (maxsize == maxalloc);
 
+  gst_buffer_resize (buf, 0, 0);
+  size = gst_buffer_get_sizes (buf, &offset, &maxsize);
+  fail_unless (size == 0);
+  fail_unless (offset == 0);
+  fail_unless (maxsize == maxalloc);
+
+  gst_buffer_resize (buf, 0, 100);
+  size = gst_buffer_get_sizes (buf, &offset, &maxsize);
+  fail_unless (size == 100);
+  fail_unless (offset == 0);
+  fail_unless (maxsize == maxalloc);
+
+  gst_buffer_resize (buf, 0, 100);
+  size = gst_buffer_get_sizes (buf, &offset, &maxsize);
+  fail_unless (size == 100);
+  fail_unless (offset == 0);
+  fail_unless (maxsize == maxalloc);
+
   gst_buffer_unref (buf);
 }
 
-- 
2.7.4