From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Thu, 23 Feb 2023 14:10:43 +0000 (+0200)
Subject: lib: istream - Don't call memcpy() with NULL parameter --with-devel-checks
X-Git-Tag: 2.4.0~2955
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=81b3a84ab1f90baf21453b707e30b9fd6d4ea44a;p=thirdparty%2Fdovecot%2Fcore.git

lib: istream - Don't call memcpy() with NULL parameter --with-devel-checks
---

diff --git a/src/lib/istream.c b/src/lib/istream.c
index 5fabe1e3f4..073662fdd6 100644
--- a/src/lib/istream.c
+++ b/src/lib/istream.c
@@ -291,13 +291,14 @@ ssize_t i_stream_read(struct istream *stream)
 	bool invalid = i_stream_is_buffer_invalid(_stream);
 
 	i_assert(prev_skip <= prev_pos);
+	size_t prev_size = prev_pos - prev_skip;
 	if (invalid)
 		;
-	else if (prev_pos - prev_skip <= 4)
-		memcpy(prev_buf, prev_data + prev_skip, prev_pos - prev_skip);
-	else {
+	else if (prev_size > 4) {
 		memcpy(prev_buf, prev_data + prev_skip, 2);
 		memcpy(prev_buf+2, prev_data + prev_pos - 2, 2);
+	} else if (prev_size > 0) {
+		memcpy(prev_buf, prev_data + prev_skip, prev_size);
 	}
 #endif