rtmpsrc: check for failed RTMP context alloc

Avoids an unlikely crash.

Arguably, if allocation fails we have no chance of
recovering but nonetheless, RTMP_Alloc can fail and
librtmp's RTMP_init() (called next) assumes a non-NULL
pointer is passed without checking.

Additionally, unify exit path on error.

1 files changed, 15 insertions, 6 deletions

diff --git a/ext/rtmp/gstrtmpsrc.c b/ext/rtmp/gstrtmpsrc.c
index 46918e755..02cbec1d1 100644
--- a/ext/rtmp/gstrtmpsrc.c
+++ b/ext/rtmp/gstrtmpsrc.c
@@ -575,13 +575,17 @@ gst_rtmp_src_start (GstBaseSrc * basesrc)
   src->discont = TRUE;
 
   src->rtmp = RTMP_Alloc ();
+
+  if (!src->rtmp) {
+    GST_ERROR_OBJECT (src, "Could not allocate librtmp's RTMP context");
+    goto error;
+  }
+
   RTMP_Init (src->rtmp);
   if (!RTMP_SetupURL (src->rtmp, src->uri)) {
     GST_ELEMENT_ERROR (src, RESOURCE, OPEN_READ, (NULL),
         ("Failed to setup URL '%s'", src->uri));
-    RTMP_Free (src->rtmp);
-    src->rtmp = NULL;
-    return FALSE;
+    goto error;
   }
   src->seekable = !(src->rtmp->Link.lFlags & RTMP_LF_LIVE);
   GST_INFO_OBJECT (src, "seekable %d", src->seekable);
@@ -591,13 +595,18 @@ gst_rtmp_src_start (GstBaseSrc * basesrc)
     if (!RTMP_Connect (src->rtmp, NULL)) {
       GST_ELEMENT_ERROR (src, RESOURCE, OPEN_READ, (NULL),
           ("Could not connect to RTMP stream \"%s\" for reading", src->uri));
-      RTMP_Free (src->rtmp);
-      src->rtmp = NULL;
-      return FALSE;
+      goto error;
     }
   }
 
   return TRUE;
+
+error:
+  if (src->rtmp) {
+    RTMP_Free (src->rtmp);
+    src->rtmp = NULL;
+  }
+  return FALSE;
 }
 
 #undef STR2AVAL