zig

commit 3b622f4494b8fd899abc20e75e46726344f2d20c (tree)
parent c4d0f97b4c3f85796c4953d6e87b5c0186616bc1
Author: Andrew Kelley <andrew@ziglang.org>
Date:   Sun,  9 Feb 2020 14:56:19 -0500

fix off-by-one error in std.unicode.utf8ToUtf16LeWithNull

and fix larger-than-one-byte sentinels when being freed

Thank you to João Pedro for identifying both problems and
providing example code to solve them.

closes #4413

Diffstat:
M
lib/std/mem.zig
 | 
2
+-
M
lib/std/unicode.zig
 | 
9
++++++---

2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/lib/std/mem.zig b/lib/std/mem.zig
@@ -233,7 +233,7 @@ pub const Allocator = struct {
     pub fn free(self: *Allocator, memory: var) void {
         const Slice = @typeInfo(@TypeOf(memory)).Pointer;
         const bytes = @sliceToBytes(memory);
-        const bytes_len = bytes.len + @boolToInt(Slice.sentinel != null);
+        const bytes_len = bytes.len + if (Slice.sentinel != null) @sizeOf(Slice.child) else 0;
         if (bytes_len == 0) return;
         const non_const_ptr = @intToPtr([*]u8, @ptrToInt(bytes.ptr));
         @memset(non_const_ptr, undefined, bytes_len);
diff --git a/lib/std/unicode.zig b/lib/std/unicode.zig
@@ -571,8 +571,9 @@ pub fn utf8ToUtf16LeWithNull(allocator: *mem.Allocator, utf8: []const u8) ![:0]u
         }
     }
 
+    const len = result.len;
     try result.append(0);
-    return result.toOwnedSlice()[0..:0];
+    return result.toOwnedSlice()[0..len :0];
 }
 
 /// Returns index of next character. If exact fit, returned index equals output slice length.
@@ -619,12 +620,14 @@ test "utf8ToUtf16LeWithNull" {
         var bytes: [128]u8 = undefined;
         const allocator = &std.heap.FixedBufferAllocator.init(bytes[0..]).allocator;
         const utf16 = try utf8ToUtf16LeWithNull(allocator, "𐐷");
-        testing.expectEqualSlices(u8, "\x01\xd8\x37\xdc\x00\x00", @sliceToBytes(utf16[0..]));
+        testing.expectEqualSlices(u8, "\x01\xd8\x37\xdc", @sliceToBytes(utf16[0..]));
+        testing.expect(utf16[2] == 0);
     }
     {
         var bytes: [128]u8 = undefined;
         const allocator = &std.heap.FixedBufferAllocator.init(bytes[0..]).allocator;
         const utf16 = try utf8ToUtf16LeWithNull(allocator, "\u{10FFFF}");
-        testing.expectEqualSlices(u8, "\xff\xdb\xff\xdf\x00\x00", @sliceToBytes(utf16[0..]));
+        testing.expectEqualSlices(u8, "\xff\xdb\xff\xdf", @sliceToBytes(utf16[0..]));
+        testing.expect(utf16[2] == 0);
     }
 }