From a05819736f348d0c5ac8b4966ac6b04c21e1a391 Mon Sep 17 00:00:00 2001
From: Timo Sirainen <timo.sirainen@dovecot.fi>
Date: Sat, 19 Nov 2016 01:59:03 +0200
Subject: [PATCH] global: Avoid loops unnecessarily decreasing below zero.

Avoids complains from clang -fsanitize=integer
---
 src/lib-mail/message-address.c |  3 ++-
 src/lib-mail/message-snippet.c |  3 ++-
 src/lib/sha3.c                 | 11 ++++++++---
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/lib-mail/message-address.c b/src/lib-mail/message-address.c
index 64f9da22b1..90b1175f9a 100644
--- a/src/lib-mail/message-address.c
+++ b/src/lib-mail/message-address.c
@@ -337,7 +337,8 @@ static int parse_address_list(struct message_address_parser_context *ctx,
 	int ret = 0;
 
 	/* address-list    = (address *("," address)) / obs-addr-list */
-	while (max_addresses-- > 0) {
+	while (max_addresses > 0) {
+		max_addresses--;
 		if ((ret = parse_address(ctx)) == 0)
 			break;
 		if (*ctx->parser.data != ',') {
diff --git a/src/lib-mail/message-snippet.c b/src/lib-mail/message-snippet.c
index b46d2d7ff1..2f3cf42750 100644
--- a/src/lib-mail/message-snippet.c
+++ b/src/lib-mail/message-snippet.c
@@ -75,8 +75,9 @@ static bool snippet_generate(struct snippet_context *ctx,
 				if (ctx->chars_left-- == 0)
 					return FALSE;
 			}
-			if (ctx->chars_left-- == 0)
+			if (ctx->chars_left == 0)
 				return FALSE;
+			ctx->chars_left--;
 			count = uni_utf8_char_bytes(data[i]);
 			i_assert(i + count <= size);
 			str_append_n(ctx->snippet, data + i, count);
diff --git a/src/lib/sha3.c b/src/lib/sha3.c
index d1e298954f..8cf61fa18d 100644
--- a/src/lib/sha3.c
+++ b/src/lib/sha3.c
@@ -144,9 +144,11 @@ void sha3_loop(void *context, const void *data, size_t len)
 	if(len < old_tail) { /* have no complete word or haven't started
 			      * the word yet */
 		/* endian-independent code follows: */
-		while (len-- > 0)
+		while (len > 0) {
+			len--;
 			ctx->saved |= (uint64_t) (*(buf++)) <<
 					((ctx->byteIndex++) * 8);
+		}
 		i_assert(ctx->byteIndex < 8);
 		return;
 	}
@@ -154,9 +156,11 @@ void sha3_loop(void *context, const void *data, size_t len)
 	if(old_tail != 0) { /* will have one word to process */
 		/* endian-independent code follows: */
 		len -= old_tail;
-		while (old_tail-- > 0)
+		while (old_tail > 0) {
+			old_tail--;
 			ctx->saved |= (uint64_t) (*(buf++)) <<
 				((ctx->byteIndex++) * 8);
+		}
 
 		/* now ready to add saved to the sponge */
 		ctx->s[ctx->wordIndex] ^= ctx->saved;
@@ -200,7 +204,8 @@ void sha3_loop(void *context, const void *data, size_t len)
 
 	/* finally, save the partial word */
 	i_assert(ctx->byteIndex == 0 && tail < 8);
-	while (tail-- > 0) {
+	while (tail > 0) {
+		tail--;
 		ctx->saved |= (uint64_t) (*(buf++)) << ((ctx->byteIndex++) * 8);
 	}
 	i_assert(ctx->byteIndex < 8);