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| author | Peter Collingbourne <peter@pcc.me.uk> | 2017-12-19 23:33:16 +0000 |
|---|---|---|
| committer | Peter Collingbourne <peter@pcc.me.uk> | 2017-12-19 23:33:16 +0000 |
| commit | 22c651c5770572641eaa16423b19e867f5f61d6b (patch) | |
| tree | dd81257e2d9e5b0a97fd44be0a6bd7dce443644c /libcxx/include/sstream | |
| parent | 7e13aef4281a275b8884bf14d1bdd6c7e0e9375c (diff) | |
| download | bcm5719-llvm-22c651c5770572641eaa16423b19e867f5f61d6b.tar.gz bcm5719-llvm-22c651c5770572641eaa16423b19e867f5f61d6b.zip | |
libcxx: Fix for basic_stringbuf::seekoff() after r320604.
As a result of this change, the basic_stringbuf constructor that
takes a mode ends up leaving __hm_ set to 0, causing the comparison
"__hm_ - __str_.data() < __noff" in seekoff() to succeed, which caused
the function to incorrectly return -1. The fix is to account for the
possibility of __hm_ being 0 when computing the distance from __hm_
to the start of the string.
Differential Revision: https://reviews.llvm.org/D41319
llvm-svn: 321124
Diffstat (limited to 'libcxx/include/sstream')
| -rw-r--r-- | libcxx/include/sstream | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/libcxx/include/sstream b/libcxx/include/sstream index 34b0014c14a..b01f47b6872 100644 --- a/libcxx/include/sstream +++ b/libcxx/include/sstream @@ -577,6 +577,7 @@ basic_stringbuf<_CharT, _Traits, _Allocator>::seekoff(off_type __off, if ((__wch & (ios_base::in | ios_base::out)) == (ios_base::in | ios_base::out) && __way == ios_base::cur) return pos_type(-1); + const ptrdiff_t __hm = __hm_ == nullptr ? 0 : __hm_ - __str_.data(); off_type __noff; switch (__way) { @@ -590,13 +591,13 @@ basic_stringbuf<_CharT, _Traits, _Allocator>::seekoff(off_type __off, __noff = this->pptr() - this->pbase(); break; case ios_base::end: - __noff = __hm_ - __str_.data(); + __noff = __hm; break; default: return pos_type(-1); } __noff += __off; - if (__noff < 0 || __hm_ - __str_.data() < __noff) + if (__noff < 0 || __hm < __noff) return pos_type(-1); if (__noff != 0) { |
