[Spice-devel] [usbredir v1] usbredirhost: Fix coverity sign_extension warning

[Victor Toso]

Complain from coverity:
 usbredir-0.7.1/usbredirhost/usbredirhost.c:1159: sign_extension:
 Suspicious implicit sign extension: "max_packetsize" with type
 "unsigned short" (16 bits, unsigned) is promoted in
 "pkts_per_transfer * transfer_count * max_packetsize" to type "int"
 (32 bits, signed), then sign-extended to type "unsigned long"
 (64 bits, unsigned). If "pkts_per_transfer * transfer_count *
 max_packetsize" is greater than 0x7FFFFFFF, the upper bits of the
 result will all be 1.

Pretty sure that reaching 0x7FFFFFFF is improbable but let's make
coverity happy.
---
 usbredirhost/usbredirhost.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/usbredirhost/usbredirhost.c b/usbredirhost/usbredirhost.c
index 2b3ee74..22c5e39 100644
--- a/usbredirhost/usbredirhost.c
+++ b/usbredirhost/usbredirhost.c
@@ -1156,7 +1156,9 @@ static void usbredirhost_stop_stream(struct usbredirhost *host,
 static void usbredirhost_set_iso_threshold(struct usbredirhost *host,
     uint8_t pkts_per_transfer, uint8_t transfer_count, uint16_t max_packetsize)
 {
-    uint64_t reference = pkts_per_transfer * transfer_count * max_packetsize;
+    uint64_t reference = (size_t) (pkts_per_transfer * transfer_count);
+    reference *= (size_t) max_packetsize;
+
     host->iso_threshold.lower = reference / 2;
     host->iso_threshold.higher = reference * 3;
     DEBUG("higher threshold is %" PRIu64 " bytes | lower threshold is %" PRIu64 " bytes",
-- 
2.7.4