diff options
| -rw-r--r-- | src/regex/regcomp.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/regex/regcomp.c b/src/regex/regcomp.c index fb24556e..b4b81968 100644 --- a/src/regex/regcomp.c +++ b/src/regex/regcomp.c @@ -409,6 +409,8 @@ typedef struct { int position; /* The highest back reference or -1 if none seen so far. */ int max_backref; + /* Bit mask of submatch IDs that can be back referenced. */ + int backref_ok; /* Compilation flags. */ int cflags; } tre_parse_ctx_t; @@ -769,6 +771,8 @@ static reg_errcode_t marksub(tre_parse_ctx_t *ctx, tre_ast_node_t *node, int sub node->submatch_id = subid; node->num_submatches++; ctx->n = node; + if (subid < 10) + ctx->backref_ok |= 1<<subid; return REG_OK; } @@ -864,6 +868,8 @@ static reg_errcode_t parse_atom(tre_parse_ctx_t *ctx, const char *s) if (!ere && (unsigned)*s-'1' < 9) { /* back reference */ int val = *s - '0'; + if (!(ctx->backref_ok & 1<<val)) + return REG_ESUBREG; node = tre_ast_new_literal(ctx->mem, BACKREF, val, ctx->position++); ctx->max_backref = MAX(val, ctx->max_backref); } else { |