zig

commit 236db6232fa2beb97c47e3f1edcdb2a29e59d160 (tree)
parent 1ed8c54cd349497adb264b0502783a6422e4f2d1
Author: root <fancl20@gmail.com>
Date:   Tue, 26 Jan 2021 22:40:34 +1100

Fix interger overflow when calling joinZ with empty slices

Diffstat:
M
lib/std/mem.zig
 | 
13
++++++++++++-

1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/lib/std/mem.zig b/lib/std/mem.zig
@@ -1507,7 +1507,7 @@ pub fn joinZ(allocator: *Allocator, separator: []const u8, slices: []const []con
 }
 
 fn joinMaybeZ(allocator: *Allocator, separator: []const u8, slices: []const []const u8, zero: bool) ![]u8 {
-    if (slices.len == 0) return &[0]u8{};
+    if (slices.len == 0) return if (zero) try allocator.dupe(u8, &[1]u8{0}) else &[0]u8{};
 
     const total_len = blk: {
         var sum: usize = separator.len * (slices.len - 1);
@@ -1536,6 +1536,11 @@ fn joinMaybeZ(allocator: *Allocator, separator: []const u8, slices: []const []co
 
 test "mem.join" {
     {
+        const str = try join(testing.allocator, ",", &[_][]const u8{});
+        defer testing.allocator.free(str);
+        testing.expect(eql(u8, str, ""));
+    }
+    {
         const str = try join(testing.allocator, ",", &[_][]const u8{ "a", "b", "c" });
         defer testing.allocator.free(str);
         testing.expect(eql(u8, str, "a,b,c"));
@@ -1554,6 +1559,12 @@ test "mem.join" {
 
 test "mem.joinZ" {
     {
+        const str = try joinZ(testing.allocator, ",", &[_][]const u8{});
+        defer testing.allocator.free(str);
+        testing.expect(eql(u8, str, ""));
+        testing.expectEqual(str[str.len], 0);
+    }
+    {
         const str = try joinZ(testing.allocator, ",", &[_][]const u8{ "a", "b", "c" });
         defer testing.allocator.free(str);
         testing.expect(eql(u8, str, "a,b,c"));