Safe guard in case of imporper data is provided to elog()

in multi-byte build.

diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 92ef224485d551a4a610700d9e13e43175c75d8e..81c462f74f1ff3862f7e6082e97230809457d83d 100644 (file)
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -683,6 +683,8 @@ write_syslog(int level, const char *line)
 #ifdef MULTIBYTE
                        /* trim to multibyte letter boundary */ 
                        buflen = pg_mbcliplen(buf, l, l);
+                       if (buflen <= 0)
+                           return;
                        buf[buflen] = '\0';
                        l = strlen(buf);
 #endif