From 443ae1d76e83db73ec5db8b89bc5aacd5b9287a1 Mon Sep 17 00:00:00 2001
From: penguindark <57967770+penguindark@users.noreply.github.com>
Date: Sun, 3 Jan 2021 16:59:00 +0100
Subject: [PATCH] regex: fix a bug in find and find_all (#7839)

---
 vlib/regex/regex_test.v | 16 +++++++++++++++-
 vlib/regex/regex_util.v | 36 ++++++++++++++++++++++++++++++++----
 2 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/vlib/regex/regex_test.v b/vlib/regex/regex_test.v
index 1ed54769cc..972351838f 100644
--- a/vlib/regex/regex_test.v
+++ b/vlib/regex/regex_test.v
@@ -271,6 +271,18 @@ find_all_test_suite = [
 		r"url *= *https?://.*"+'\n',
 		[5, 45],
 		['url = https://github.com/dario/pig.html\n']
+	},
+	Test_find_all{
+		"#.#......##.#..#..##........##....###...##...######.......#.....#..#......#...#........###.#..#.",
+		r"#[.#]{4}##[.#]{4}##[.#]{4}###",
+		[29, 49],
+		['#....###...##...####']
+	},
+		Test_find_all{
+		"#.#......##.#..#..##........##....###...##...######.......#.....#..#......#...#........###.#..#.",
+		r".*#[.#]{4}##[.#]{4}##[.#]{4}###",
+		[0, 49],
+		['#.#......##.#..#..##........##....###...##...####']
 	}
 ]
 )
@@ -283,7 +295,9 @@ fn test_regex(){
 	// check capturing groups
 	for c,to in cgroups_test_suite {
 		// debug print
-		if debug { println("#$c [$to.src] q[$to.q] ($to.s, $to.e)") }
+		if debug {
+			println("$c [${to.src}] [q${to.q}] (${to.s}, ${to.e})") 
+		}
 
 		mut re := regex.regex_opt(to.q) or {
 			eprintln('err: $err')
diff --git a/vlib/regex/regex_util.v b/vlib/regex/regex_util.v
index 27918d0ab3..ff7eddf983 100644
--- a/vlib/regex/regex_util.v
+++ b/vlib/regex/regex_util.v
@@ -116,9 +116,10 @@ pub fn (re RE) get_group_list() []Re_group {
 * Finders
 *
 ******************************************************************************/
-// find try to find the first match in the input string
+/*
+// find internal implementation
 [direct_array_access]
-pub fn (mut re RE) find(in_txt string) (int,int) {
+fn (mut re RE) find_imp(in_txt string) (int,int) {
 	old_flag := re.flag
 	re.flag |= f_src  // enable search mode
 
@@ -134,6 +135,33 @@ pub fn (mut re RE) find(in_txt string) (int,int) {
 	}
 	return no_match_found, 0
 }
+*/
+
+// find try to find the first match in the input string
+[direct_array_access]
+pub fn (mut re RE) find(in_txt string) (int,int) {
+	mut i := 0
+	for i < in_txt.len {
+		//--- speed references ---
+		mut s := -1
+		mut e := -1
+		unsafe {
+			tmp_str := tos(in_txt.str+i, in_txt.len-i)
+			s,e = re.match_string(tmp_str)
+		}
+		//------------------------
+		//s,e := re.find_imp(in_txt[i..])
+		//------------------------
+		if s >= 0 && e > s {
+			//println("find match in: ${i+s},${i+e} [${in_txt[i+s..i+e]}]")
+			return i+s, i+e
+		} else {
+			i++
+		}
+
+	}
+	return -1, -1
+}
 
 // find_all find all the non overlapping occurrences of the match pattern
 [direct_array_access]
@@ -148,10 +176,10 @@ pub fn (mut re RE) find_all(in_txt string) []int {
 		mut e := -1
 		unsafe {
 			tmp_str := tos(in_txt.str+i, in_txt.len-i)
-			s,e = re.find(tmp_str)
+			s,e = re.match_string(tmp_str)
 		}
 		//------------------------
-		//s,e := re.find(in_txt[i..])
+		//s,e := re.find_imp(in_txt[i..])
 		//------------------------
 		if s >= 0 && e > s && i+s > ls {
 			//println("find match in: ${i+s},${i+e} [${in_txt[i+s..i+e]}] ls:$ls")