From b294e14ce4b9d1ccab0368eede4f746dfc7c6062 Mon Sep 17 00:00:00 2001
From: Andreas Linz <anli@spreadshirt.net>
Date: Wed, 16 Dec 2020 21:17:41 +0100
Subject: [PATCH] Truncate user and group ids

Calls to `getuid`, `getgid` and their `eid` variants fail to compile on
64bit Linux systems because the return value of the syscall is of
`usize` and needs to be truncated to fit the size of `uid_t` that is 32
bit.

Thanks to @FireFox317 for figuring this out in Zig's Discord channel!
---
 lib/std/os/linux.zig | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index f840f6a255be..3beeb0e13c25 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -747,7 +747,7 @@ pub fn getuid() uid_t {
     if (@hasField(SYS, "getuid32")) {
         return @as(uid_t, syscall0(.getuid32));
     } else {
-        return @as(uid_t, syscall0(.getuid));
+        return @truncate(uid_t, syscall0(.getuid));
     }
 }
 
@@ -755,7 +755,7 @@ pub fn getgid() gid_t {
     if (@hasField(SYS, "getgid32")) {
         return @as(gid_t, syscall0(.getgid32));
     } else {
-        return @as(gid_t, syscall0(.getgid));
+        return @truncate(gid_t, syscall0(.getgid));
     }
 }
 
@@ -763,7 +763,7 @@ pub fn geteuid() uid_t {
     if (@hasField(SYS, "geteuid32")) {
         return @as(uid_t, syscall0(.geteuid32));
     } else {
-        return @as(uid_t, syscall0(.geteuid));
+        return @truncate(uid_t, syscall0(.geteuid));
     }
 }
 
@@ -771,7 +771,7 @@ pub fn getegid() gid_t {
     if (@hasField(SYS, "getegid32")) {
         return @as(gid_t, syscall0(.getegid32));
     } else {
-        return @as(gid_t, syscall0(.getegid));
+        return @truncate(gid_t, syscall0(.getegid));
     }
 }