[hackers] [st][PATCH] fix pointer to one before object UB

[Guilherme Janczak]

The expression "s + strlen(s) - 1" can create a pointer to one before 
*s if strlen(s) is 0.

---
 util.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/util.c b/util.c
index bdba718..c97f491 100644
--- a/util.c
+++ b/util.c
@@ -59,9 +59,13 @@ skip(char *s, char c) {
 static void
 trim(char *s) {
        char *e;
-
-       e = s + strlen(s) - 1;
-       while(isspace(*e) && e > s)
-               e--;
-       *(e + 1) = '\0';
+       
+       e = s + strlen(s);
+       while (e > s) {
+               if (!isspace(*--e)) {
+                       e++;
+                       *e = '\0';
+                       break;
+               }
+       }
 }
-- 
2.31.1