fix argsAlloc buffer size

The buffer `buf` contains N (= `slice_sizes.len`) slices followed by the
N null-terminated arguments. The N null-terminated arguments are stored
in the `contents` array list. Thus, `buf` size should be:
    @sizeOf([]u8) * slice_sizes.len + contents_slice.len

Instead of:
    @sizeOf([]u8) * slice_sizes.len + contents_slice.len + slice_sizes.len

This bug was found thanks to the gpa allocator which checks if freed
size matches allocated sizes for large allocations.

1 files changed, 1 insertions, 2 deletions

diff --git a/lib/std/process.zig b/lib/std/process.zig
index 70695f9cbc..9e1abb4479 100644
--- a/lib/std/process.zig
+++ b/lib/std/process.zig
@@ -557,9 +557,8 @@ pub fn argsAlloc(allocator: mem.Allocator) ![][:0]u8 {
 
     const contents_slice = contents.items;
     const slice_sizes = slice_list.items;
-    const contents_size_bytes = try math.add(usize, contents_slice.len, slice_sizes.len);
     const slice_list_bytes = try math.mul(usize, @sizeOf([]u8), slice_sizes.len);
-    const total_bytes = try math.add(usize, slice_list_bytes, contents_size_bytes);
+    const total_bytes = try math.add(usize, slice_list_bytes, contents_slice.len);
     const buf = try allocator.alignedAlloc(u8, @alignOf([]u8), total_bytes);
     errdefer allocator.free(buf);