On 20/06/19 00:00 +0100, Jonathan Wakely wrote:
The change in r263433 broke the contract of the __rotate functions, by no longer accepting empty ranges. That means that callers which inlined the old version of std::rotate (without checks) that end up linking to a new definition of std::__rotate (also without checks) could perform a divide by zero and crash.This restores the old contract of the __rotate overloads. PR libstdc++/90920 partially revert r263433 * include/bits/stl_algo.h (__rotate): Restore checks for empty ranges. (rotate): Remove checks. * testsuite/25_algorithms/rotate/90920.cc: New test. Tested x86_64-linux, committed to trunk. This needs to be backported to gcc-9-branch too.
Committed to gcc-9-branch. I will also add a notice to the https://gcc.gnu.org/gcc-9/changes.html page.
