From: Martin Lewis <martin.lewis.x84@gmail.com>
Date: Sun, 15 Sep 2019 16:51:30 +0000 (+0200)
Subject: replace: count_strstr - Handle an edge case where sub is empty
X-Git-Tag: 1_32_0~139
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=7011eca83afc313098f9869eea36742d4506bc02;p=oweals%2Fbusybox.git

replace: count_strstr - Handle an edge case where sub is empty

If sub is empty, avoids an infinite loop.

function                                             old     new   delta
count_strstr                                          45      63     +18

Signed-off-by: Martin Lewis <martin.lewis.x84@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---

diff --git a/libbb/replace.c b/libbb/replace.c
index a661d96e6..6183d3e6f 100644
--- a/libbb/replace.c
+++ b/libbb/replace.c
@@ -15,6 +15,10 @@ unsigned FAST_FUNC count_strstr(const char *str, const char *sub)
 	size_t sub_len = strlen(sub);
 	unsigned count = 0;
 
+	/* If sub is empty, avoid an infinite loop */
+	if (sub_len == 0)
+		return strlen(str) + 1;
+
 	while ((str = strstr(str, sub)) != NULL) {
 		count++;
 		str += sub_len;