From 874aca4a86d303ec286312a421b74994f422e9d4 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Mon, 1 Aug 2022 18:30:50 +0200
Subject: [PATCH] Avoid an endless loop: Safeguard function
 search_plain_identifier(char *str, const char *identifier) against
 identifiers being an empty string.

---
 src/frontend/inpcom.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/frontend/inpcom.c b/src/frontend/inpcom.c
index 516ba5d40..8c627337e 100644
--- a/src/frontend/inpcom.c
+++ b/src/frontend/inpcom.c
@@ -5168,10 +5168,11 @@ char *ya_search_identifier(char *str, const char *identifier, char *str_begin)
     return str;
 }
 
-
+/* Check for 'identifier' being in string str, surrounded by chars
+   not being a member of alphanumeric or '_' characters. */
 char *search_plain_identifier(char *str, const char *identifier)
 {
-    if (str && identifier) {
+    if (str && identifier && *identifier != '\0') {
         char *str_begin = str;
         while ((str = strstr(str, identifier)) != NULL) {
             char before;