From daf4ef50c88c2b9a6bf2c40b537eebc202caad6e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?S=C3=A9bastien=20Gonzalve?= Date: Sat, 14 Nov 2020 10:39:47 +0100 Subject: [PATCH] Do not try to access element when vector is empty Trying to access tmp[0] causes a crash on Fedora when assertion on STL are enabled. /usr/include/c++/10/bits/stl_vector.h:1045: std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) [with _Tp = unsigned char; _Alloc = std::allocator; std::vector<_Tp, _Alloc>::reference = unsigned char&; std::vector<_Tp, _Alloc>::size_type = long unsigned int]: Assertion '__builtin_expect(__n < this->size(), true)' failed. This patch just passes nullptr as pointer to getSortKey() when tmp size is 0, preventing dereferencing elements in empty vector. I guess that &tmp[0] should be optimized as 'no real access' when disabling assertion, but actually leads to crash when assert are enabled. --- src/icu/collator.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libs/locale/src/icu/collator.cpp b/libs/locale/src/icu/collator.cpp index 7f1ea6a..dc59e8c 100644 --- a/libs/locale/src/icu/collator.cpp +++ b/libs/locale/src/icu/collator.cpp @@ -93,7 +93,7 @@ namespace boost { std::vector tmp; tmp.resize(str.length()); icu::Collator *collate = get_collator(level); - int len = collate->getSortKey(str,&tmp[0],tmp.size()); + int len = collate->getSortKey(str,tmp.empty()?nullptr:&tmp[0],tmp.size()); if(len > int(tmp.size())) { tmp.resize(len); collate->getSortKey(str,&tmp[0],tmp.size()); -- 2.26.2