idmap-hash: Attempt to fix Coverity ID 709116 Overflowed array index write

Signed-off-by: Michael Adam <obnox@samba.org>
Autobuild-User(master): Michael Adam <obnox@samba.org>
Autobuild-Date(master): Wed Jun 20 12:53:59 CEST 2012 on sn-devel-104

diff --git a/source3/winbindd/idmap_hash/mapfile.c b/source3/winbindd/idmap_hash/mapfile.c
index ec846f37eb69b726df1cb508d2a458f90914f7ec..a0e2b489cbb0e1f76a6caaa60adeb1a63f112e45 100644 (file)
--- a/source3/winbindd/idmap_hash/mapfile.c
+++ b/source3/winbindd/idmap_hash/mapfile.c
@@ -74,7 +74,12 @@ static bool mapfile_read_line(fstring key, fstring value)
 
        /* Strip newlines and carriage returns */
 
-       len = strlen_m(buffer) - 1;
+       len = strlen_m(buffer);
+       if (len == 0) {
+               return false;
+       }
+       len -= 1;
+
        while ((buffer[len] == '\n') || (buffer[len] == '\r')) {
                buffer[len--] = '\0';
        }