Bug 12713 – [REG 2.066A] std.regex.regex crashes with SEGV, illegal instruction resp. assertion failure with certain bad input

Created attachment 1356 Source code for test case The bad regular expression "[[a-z]([a-z]|(([[a-z])))" seems to run an unexpected execution path during regular expression compilation which ended up in a segmentation fault (if compiled with -release) or an assertion failure (if not). Verified with dmd 2.065 and ldc2-0.12-1 (the latter causes an 'illegal instruction' crash if compiled with -release). Instead of crashing, the bad expression should be rejected with a proper exception like "wrong character class" (as for other syntactically wrong expressions). Note: the terms "[[a-z]" were intended to be "[\\[a-z]".

Is a git-head regression introduced in : https://github.com/DmitryOlshansky/phobos/commit/cef454d43280346c52197f785171bb400ef169ec

Commits pushed to master at https://github.com/D-Programming-Language/phobos https://github.com/D-Programming-Language/phobos/commit/0507fd70e87de758f28347ba408912e7a4186978 Fix issue 12713 std.regex.regex crashes with SEGV, illegal instruction resp. assertion failure with certain bad input https://github.com/D-Programming-Language/phobos/commit/d1e2f2b0650158e4aa7cab536fde24200c6e6e4a Merge pull request #2165 from DmitryOlshansky/issue-12713 Fix issue 12713 std.regex.regex crashes with SEGV, illegal instruction r...