From: Andre Noll <maan@systemlinux.org>
Date: Tue, 10 Apr 2012 05:38:20 +0000 (+0200)
Subject: flacdec_close(): Be liberal in what you accept.
X-Git-Tag: v0.4.11~13^2~2
X-Git-Url: http://git.tue.mpg.de/?a=commitdiff_plain;h=1e196821cc4fa9e1319557ce1100961be6795278;p=paraslash.git

flacdec_close(): Be liberal in what you accept.

Functions like close() which terminate an instance of some subsystem
should always be idempotent, i.e. when calling such a function twice
with the same argument, the second call should be a noop.

However, flacdec_close() violates this rule because it dereferences
its private pointer unconditionally. This patch makes the function
idempotent.
---

diff --git a/flacdec_filter.c b/flacdec_filter.c
index 40246f24..cd086f45 100644
--- a/flacdec_filter.c
+++ b/flacdec_filter.c
@@ -264,10 +264,17 @@ out:
 
 static void flacdec_close(struct filter_node *fn)
 {
-	struct private_flacdec_data *pfd = fn->private_data;
+	struct private_flacdec_data *pfd;
 
-	FLAC__stream_decoder_finish(pfd->decoder);
-	FLAC__stream_decoder_delete(pfd->decoder);
+	if (!fn)
+		return;
+	pfd = fn->private_data;
+	if (!pfd)
+		return;
+	if (pfd->decoder) {
+		FLAC__stream_decoder_finish(pfd->decoder);
+		FLAC__stream_decoder_delete(pfd->decoder);
+	}
 	free(pfd);
 	fn->private_data = NULL;
 }