From e0ab706af6691a8156b2ed7fe29b6c60792ea46a Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@systemlinux.org>
Date: Tue, 13 Nov 2007 20:13:02 +0100
Subject: [PATCH] Fix tv_divide().

The old code contained an integer overflow which caused the mp3 audio
format handler to compute the chunk of large mp3 files incorrectly.

Moreover, the code was more complicated than necessary. So replace it
by a simple calculation which just transforms the given struct timeval
into its number of microseconds, does the division and transforms
the quotient back to a struct timeval.

Thanks to Gerrit Renker for pointing out the problem.
---
 time.c | 17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/time.c b/time.c
index 83231c89..6672dca4 100644
--- a/time.c
+++ b/time.c
@@ -113,21 +113,10 @@ void tv_scale(const unsigned long mult, const struct timeval *tv,
 void tv_divide(const unsigned long divisor, const struct timeval *tv,
 	struct timeval *result)
 {
-	long unsigned q;
+	uint64_t x = ((uint64_t)tv->tv_sec * 1000 * 1000 + tv->tv_usec) / divisor;
 
-	if (!divisor) {
-		PARA_EMERG_LOG("%s\n", "division by zero");
-		exit(EXIT_FAILURE);
-	}
-	q = tv->tv_usec / divisor;
-	result->tv_sec = tv->tv_sec / divisor;
-	result->tv_usec = (tv->tv_sec - result->tv_sec * divisor)
-		* 1000 * 1000 / divisor;
-	if (result->tv_usec + q >= 1000 * 1000) {
-		result->tv_sec++;
-		result->tv_usec = 1000 * 1000 - result->tv_usec - q;
-	} else
-		result->tv_usec += q;
+	result->tv_sec = x / 1000 / 1000;
+	result->tv_usec = x % (1000 * 1000);
 }
 
 /**
-- 
2.39.5