Fixed strreplace() in case the search string is empty

CONTRIBUTORS

@@ -3388,6 +3388,7 @@ Stefan Hofmann <stefan.hofmann@t-online.de>
  for reporting missing setting the file name of the info file after renaming a recording
  for adding '~' to the list of delimiters in cTextWrapper
  for suggesting to delete old recording info before reading modified info file
+ for fixing strreplace() in case the search string is empty
 
 Stefan Blochberger <Stefan.Blochberger@gmx.de>
  for suggesting to automatically display the progress display whenever replay of a

HISTORY

@@ -10119,7 +10119,7 @@ Video Disk Recorder Revision History
 - Now deleting old recording info before reading modified info file (suggested by
   Stefan Hofmann).
 
-2025-06-17:
+2025-06-18:
 
 - Fixed some misplaced 'override' keywords in the 'hello' and 'skincurses' plugins.
 - cRecording now fetches priority, lifetime and framesPerSecond from cRecordingInfo.
@@ -10129,3 +10129,4 @@ Video Disk Recorder Revision History
 - Updated the Italian OSD texts (thanks to Diego Pierotto).
 - Enabled manually turning subtitles on/off in 'after rewind' mode.
 - Limiting timeouts to a minimum of 3ms to avoid problems with polls and waits if timeout is 0.
+- Fixed strreplace() in case the search string is empty (thanks to Stefan Hofmann).

tools.c

@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: tools.c 5.16 2025/06/17 20:32:06 kls Exp $
+ * $Id: tools.c 5.17 2025/06/18 08:44:47 kls Exp $
  */
 
 #include "tools.h"
@@ -154,7 +154,7 @@ char *strreplace(char *s, char c1, char c2)
 
 char *strreplace(char *s, const char *s1, const char *s2)
 {
-  if (!s || !s1 || !s2 || strcmp(s1, s2) == 0)
+  if (!s || !s1 || !*s1 || !s2 || strcmp(s1, s2) == 0)
      return s;
   char *q = s;
   if (char *p = strstr(s, s1)) {