runtime: always initialize str field in __go_string_slice result
Change-Id: I8ac935a03eff301ccf9caecc9d84a7db5e9d92aa
Reviewed-on: https://go-review.googlesource.com/64110
Reviewed-by: Than McIntosh <thanm@google.com>
diff --git a/libgo/runtime/go-strslice.c b/libgo/runtime/go-strslice.c
index 0e89781..d51c249 100644
--- a/libgo/runtime/go-strslice.c
+++ b/libgo/runtime/go-strslice.c
@@ -18,10 +18,13 @@
if (start > len || end < start || end > len)
runtime_panicstring ("string index out of bounds");
ret.len = end - start;
- // If the length of the new string is zero, don't adjust the str
- // field. This ensures that we don't create a pointer to the next
- // memory block, and thus keep it live unnecessarily.
- if (ret.len > 0)
+ // If the length of the new string is zero, the str field doesn't
+ // matter, so just set it to nil. This avoids the problem of
+ // s.str + start pointing just past the end of the string,
+ // which may keep the next memory block alive unnecessarily.
+ if (ret.len == 0)
+ ret.str = nil;
+ else
ret.str = s.str + start;
return ret;
}
