Merge remote branch 'qatar/master'

* qatar/master:
  log: Fix an oob array read.
  cosmetics: trim trailing whitespace in postproc
  Ban strncpy() it's too easy to misuse.
  psymodel: Remove wrapper functions.
  aacenc: Replace loop counters in aac_encode_frame() with more descriptive 'ch' and 'w'.
  regtest: remove redundant flags in jpg test
  regtest: use run_ffmpeg in do_image_formats
  regtest: simplify encoding functions
  ffmpeg.c: check for interlaced flag in the correct place.

Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavutil/log.c

@@ -111,7 +111,7 @@ void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl)
 
     vsnprintf(line + strlen(line), sizeof(line) - strlen(line), fmt, vl);
 
-    print_prefix= line[strlen(line)-1] == '\n';
+    print_prefix = strlen(line) && line[strlen(line)-1] == '\n';
 
 #if HAVE_ISATTY
     if(!is_atty) is_atty= isatty(2) ? 1 : -1;