diff options
| -rw-r--r-- | src/regex/regcomp.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/src/regex/regcomp.c b/src/regex/regcomp.c index ac207c89..078f657c 100644 --- a/src/regex/regcomp.c +++ b/src/regex/regcomp.c @@ -837,6 +837,10 @@ static reg_errcode_t parse_atom(tre_parse_ctx_t *ctx, const char *s) node = tre_ast_new_literal(ctx->mem, v, v, ctx->position++); s--; break; + case '{': + /* reject repetitions after empty expression in BRE */ + if (!ere) + return REG_BADRPT; default: if (!ere && (unsigned)*s-'1' < 9) { /* back reference */ @@ -880,10 +884,14 @@ static reg_errcode_t parse_atom(tre_parse_ctx_t *ctx, const char *s) s++; break; case '*': - case '|': + return REG_BADPAT; case '{': case '+': case '?': + /* reject repetitions after empty expression in ERE */ + if (ere) + return REG_BADRPT; + case '|': if (!ere) goto parse_literal; case 0: @@ -964,8 +972,9 @@ static reg_errcode_t tre_parse(tre_parse_ctx_t *ctx) } parse_iter: - /* extension: repetitions are accepted after an empty node - eg. (+), ^*, a$?, a|{2} */ + /* extension: repetitions are rejected after an empty node + eg. (+), |*, {2}, but assertions are not treated as empty + so ^* or $? are accepted currently. */ switch (*s) { case '+': case '?': |