From 4d034b52593c40db9ceeaa531eefdb628fa29ce5 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Mon, 18 Sep 2017 22:29:45 +0000 Subject: runtime: always initialize str field in __go_string_slice result Reviewed-on: https://go-review.googlesource.com/64110 From-SVN: r252953 --- libgo/runtime/go-strslice.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'libgo') diff --git a/libgo/runtime/go-strslice.c b/libgo/runtime/go-strslice.c index 0e897812..d51c249 100644 --- a/libgo/runtime/go-strslice.c +++ b/libgo/runtime/go-strslice.c @@ -18,10 +18,13 @@ __go_string_slice (String s, intgo start, intgo end) 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; } -- cgit v1.1