The result of one call to a function is tested, and then at the second call
to the same function, the previous result, and not the current result, is
tested again.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression ret;
identifier f;
statement S1,S2;
@@

*ret = f(...);
if (\(ret != 0\|ret < 0\|ret == NULL\)) S1
... when any
*f(...);
if (\(ret != 0\|ret < 0\|ret == NULL\)) S2
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>