Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> writes: > @@ -417,7 +415,6 @@ static void compile_fixed_regexp(struct grep_pat *p, struct grep_opt *opt) > int regflags; > > basic_regex_quote_buf(&sb, p->pattern); > - regflags = opt->regflags & ~REG_EXTENDED; > if (opt->ignore_case) > regflags |= REG_ICASE; > err = regcomp(&p->regexp, sb.buf, regflags); This hunk is wrong. Now the use of regflags we see in the post context is mixing ICASE bit into an uninitialized garbage on the stack.