From 586b34436e889c57f3108e6160f20beb55e61cd7 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Fri, 10 Mar 2017 10:13:05 +0100
Subject: [PATCH] buffer: handle gst_buffer_map failures

---
 libs/gst/check/gstharness.c          |  9 ++++++---
 plugins/elements/gstdownloadbuffer.c | 22 ++++++++++++++++++++--
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/libs/gst/check/gstharness.c b/libs/gst/check/gstharness.c
index f917786999..7a6d2aafd8 100644
--- a/libs/gst/check/gstharness.c
+++ b/libs/gst/check/gstharness.c
@@ -1741,9 +1741,12 @@ gst_harness_dump_to_file (GstHarness * h, const gchar * filename)
 
   while ((buf = g_async_queue_try_pop (priv->buffer_queue))) {
     GstMapInfo info;
-    gst_buffer_map (buf, &info, GST_MAP_READ);
-    fwrite (info.data, 1, info.size, fd);
-    gst_buffer_unmap (buf, &info);
+    if (gst_buffer_map (buf, &info, GST_MAP_READ)) {
+      fwrite (info.data, 1, info.size, fd);
+      gst_buffer_unmap (buf, &info);
+    } else {
+      GST_ERROR ("failed to map buffer %p", buf);
+    }
     gst_buffer_unref (buf);
   }
 
diff --git a/plugins/elements/gstdownloadbuffer.c b/plugins/elements/gstdownloadbuffer.c
index 36455ac246..1dea8a7e40 100644
--- a/plugins/elements/gstdownloadbuffer.c
+++ b/plugins/elements/gstdownloadbuffer.c
@@ -780,7 +780,8 @@ gst_download_buffer_read_buffer (GstDownloadBuffer * dlbuf, guint64 offset,
   else
     buf = *buffer;
 
-  gst_buffer_map (buf, &info, GST_MAP_WRITE);
+  if (!gst_buffer_map (buf, &info, GST_MAP_WRITE))
+    goto map_failed;
 
   GST_DEBUG_OBJECT (dlbuf, "Reading %u bytes from %" G_GUINT64_FORMAT, length,
       offset);
@@ -835,6 +836,14 @@ hit_eos:
     GST_DEBUG_OBJECT (dlbuf, "EOS hit");
     return GST_FLOW_EOS;
   }
+map_failed:
+  {
+    GST_ELEMENT_ERROR (dlbuf, RESOURCE, BUSY,
+        (_("Failed to map buffer.")), ("failed to map buffer in WRITE mode"));
+    if (*buffer == NULL)
+      gst_buffer_unref (buf);
+    return GST_FLOW_ERROR;
+  }
 out_flushing:
   {
     GST_DEBUG_OBJECT (dlbuf, "we are flushing");
@@ -1163,7 +1172,8 @@ gst_download_buffer_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer)
         GST_BUFFER_OFFSET (buffer), offset);
   }
 
-  gst_buffer_map (buffer, &info, GST_MAP_READ);
+  if (!gst_buffer_map (buffer, &info, GST_MAP_READ))
+    goto map_error;
 
   GST_DEBUG_OBJECT (dlbuf, "Writing %" G_GSIZE_FORMAT " bytes to %"
       G_GUINT64_FORMAT, info.size, offset);
@@ -1248,6 +1258,14 @@ out_seeking:
     gst_buffer_unref (buffer);
     return GST_FLOW_OK;
   }
+map_error:
+  {
+    GST_DOWNLOAD_BUFFER_MUTEX_UNLOCK (dlbuf);
+    gst_buffer_unref (buffer);
+    GST_ELEMENT_ERROR (dlbuf, RESOURCE, BUSY,
+        (_("Failed to map buffer.")), ("failed to map buffer in READ mode"));
+    return GST_FLOW_ERROR;
+  }
 write_error:
   {
     GST_DOWNLOAD_BUFFER_MUTEX_UNLOCK (dlbuf);