From df3f0c76eec2314ab7a23ef99d4e390d2456a1ce Mon Sep 17 00:00:00 2001 From: Laurenz Albe Date: Thu, 22 May 2025 23:05:30 +0200 Subject: [PATCH v1] Fix SIMILAR TO regex translation The code that translates SIMILAR TO pattern matching expressions to regular expressions didn't consider that brackets can be nested, as in [/_[:alpha:]@%], and replaced placeholders like _ and % where it shouldn't. --- src/backend/utils/adt/regexp.c | 19 +++++++++++++------ src/test/regress/expected/strings.out | 12 ++++++++++++ src/test/regress/sql/strings.sql | 3 +++ 3 files changed, 28 insertions(+), 6 deletions(-) diff --git a/src/backend/utils/adt/regexp.c b/src/backend/utils/adt/regexp.c index edee1f7880b..a23c4c959e4 100644 --- a/src/backend/utils/adt/regexp.c +++ b/src/backend/utils/adt/regexp.c @@ -773,7 +773,8 @@ similar_escape_internal(text *pat_text, text *esc_text) int plen, elen; bool afterescape = false; - bool incharclass = false; + int incharclass = 0; + bool charclass_start = false; int nquotes = 0; p = VARDATA_ANY(pat_text); @@ -904,7 +905,7 @@ similar_escape_internal(text *pat_text, text *esc_text) /* fast path */ if (afterescape) { - if (pchar == '"' && !incharclass) /* escape-double-quote? */ + if (pchar == '"' && incharclass < 1) /* escape-double-quote? */ { /* emit appropriate part separator, per notes above */ if (nquotes == 0) @@ -953,18 +954,24 @@ similar_escape_internal(text *pat_text, text *esc_text) /* SQL escape character; do not send to output */ afterescape = true; } - else if (incharclass) + else if (incharclass > 0) { if (pchar == '\\') *r++ = '\\'; *r++ = pchar; - if (pchar == ']') - incharclass = false; + if (pchar == '[') + incharclass++; + else if (pchar == ']' && !charclass_start) + incharclass--; + + if (pchar != '^' && charclass_start) + charclass_start = false; } else if (pchar == '[') { *r++ = pchar; - incharclass = true; + incharclass++; + charclass_start = true; } else if (pchar == '%') { diff --git a/src/test/regress/expected/strings.out b/src/test/regress/expected/strings.out index 174f0a68331..aa0bddd682c 100644 --- a/src/test/regress/expected/strings.out +++ b/src/test/regress/expected/strings.out @@ -614,6 +614,18 @@ SELECT 'abcdefg' SIMILAR TO '_bcd%' ESCAPE NULL AS null; SELECT 'abcdefg' SIMILAR TO '_bcd#%' ESCAPE '##' AS error; ERROR: invalid escape string HINT: Escape string must be empty or one character. +-- ".", "_" and "%" should be left alone in character classes +EXPLAIN (VERBOSE, COSTS OFF) +SELECT (SELECT '') SIMILAR TO '._[._[:alnum:]._]*._[]._]._[^].%].%'; + QUERY PLAN +---------------------------------------------------------------------------------------- + Result + Output: ((InitPlan 1).col1 ~ '^(?:\..[._[:alnum:]._]*\..[]._]\..[^].%]\..*)$'::text) + InitPlan 1 + -> Result + Output: ''::text +(5 rows) + -- Test backslash escapes in regexp_replace's replacement string SELECT regexp_replace('1112223333', E'(\\d{3})(\\d{3})(\\d{4})', E'(\\1) \\2-\\3'); regexp_replace diff --git a/src/test/regress/sql/strings.sql b/src/test/regress/sql/strings.sql index f7b325baadf..eb743d9e3af 100644 --- a/src/test/regress/sql/strings.sql +++ b/src/test/regress/sql/strings.sql @@ -196,6 +196,9 @@ SELECT 'abcd\efg' SIMILAR TO '_bcd\%' ESCAPE '' AS true; -- these behaviors are per spec, though: SELECT 'abcdefg' SIMILAR TO '_bcd%' ESCAPE NULL AS null; SELECT 'abcdefg' SIMILAR TO '_bcd#%' ESCAPE '##' AS error; +-- ".", "_" and "%" should be left alone in character classes +EXPLAIN (VERBOSE, COSTS OFF) +SELECT (SELECT '') SIMILAR TO '._[._[:alnum:]._]*._[]._]._[^].%].%'; -- Test backslash escapes in regexp_replace's replacement string SELECT regexp_replace('1112223333', E'(\\d{3})(\\d{3})(\\d{4})', E'(\\1) \\2-\\3'); -- 2.49.0