From d3385c8130e4af64e5b2a1648683f6ef6c279849 Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Fri, 7 Apr 2017 13:03:38 +0100
Subject: [PATCH] [Minor] Fix substring search in case if inlen == srchlen

---
 src/libutil/str_util.c | 51 +++++++++++++++++++++++-------------------
 1 file changed, 28 insertions(+), 23 deletions(-)

diff --git a/src/libutil/str_util.c b/src/libutil/str_util.c
index cb110e136..fbf223020 100644
--- a/src/libutil/str_util.c
+++ b/src/libutil/str_util.c
@@ -1229,36 +1229,41 @@ rspamd_substring_search_caseless (const gchar *in, gsize inlen,
 	gsize i, j;
 	gchar c1, c2;
 
-	if (inlen < srchlen) {
-		return -1;
-	}
+	/* Searching */
+	if (inlen > srchlen) {
+		/* Preprocessing */
+		for (d = i = 1; i < srchlen; ++i) {
+			/* computes d = 2^(m-1) with the left-shift operator */
+			d = (d << 1);
+		}
 
-	/* Preprocessing */
-	for (d = i = 1; i < srchlen; ++i) {
-		/* computes d = 2^(m-1) with the left-shift operator */
-		d = (d << 1);
-	}
+		for (hash_in = hash_srch = i = 0; i < srchlen; ++i) {
+			hash_srch = ((hash_srch << 1) + g_ascii_tolower (srch[i]));
+			hash_in = ((hash_in << 1) + g_ascii_tolower (in[i]));
+		}
 
-	for (hash_in = hash_srch = i = 0; i < srchlen; ++i) {
-		hash_srch = ((hash_srch << 1) + g_ascii_tolower (srch[i]));
-		hash_in = ((hash_in << 1) + g_ascii_tolower (in[i]));
-	}
+		j = 0;
+		while (j <= inlen - srchlen) {
 
-	/* Searching */
-	j = 0;
-	while (j <= inlen - srchlen) {
+			if (hash_srch == hash_in &&
+					rspamd_lc_cmp (srch, in + j, srchlen) == 0) {
+				return (goffset) j;
+			}
 
-		if (hash_srch == hash_in && rspamd_lc_cmp (srch, in + j, srchlen) == 0) {
-			return (goffset) j;
+			c1 = g_ascii_tolower (in[j]);
+			c2 = g_ascii_tolower (in[j + srchlen]);
+			hash_in = RKHASH (c1, c2, hash_in);
+			++j;
 		}
-
-		c1 = g_ascii_tolower (in[j]);
-		c2 = g_ascii_tolower (in[j + srchlen]);
-		hash_in = RKHASH (c1, c2, hash_in);
-		++j;
+	}
+	else if (inlen == srchlen) {
+		return rspamd_lc_cmp (srch, in, srchlen) == 0;
+	}
+	else {
+		return (-1);
 	}
 
-	return -1;
+	return (-1);
 }
 
 /* Computing of the maximal suffix for <= */
-- 
2.39.5