From 08190bbe9665b75c73453e75bd61579b18532634 Mon Sep 17 00:00:00 2001
From: Udo Hoffmann <uhf7@isoft-software.de>
Date: Wed, 14 Oct 2020 14:47:00 +0200
Subject: [PATCH] Fix RegEx look behind operations and \A and and \b and \z

Fix #713, fix #1870, fix #2216, fix #2360, fix #9004, fix #4855, close #8926, close #9008
---
 PowerEditor/installer/functionList/python.xml |  6 +++---
 PowerEditor/installer/functionList/ruby.xml   |  6 +++---
 scintilla/boostregex/BoostRegExSearch.cxx     | 13 +++----------
 3 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/PowerEditor/installer/functionList/python.xml b/PowerEditor/installer/functionList/python.xml
index a0123534..3941bb94 100644
--- a/PowerEditor/installer/functionList/python.xml
+++ b/PowerEditor/installer/functionList/python.xml
@@ -16,13 +16,13 @@
 			commentExpr="(?s:'''.*?''')|(?m-s:#.*?$)"
 		>
 			<classRange
-				mainExpr    ="(?&lt;=^class\x20).*?(?=\n\S|\Z)"
+				mainExpr    ="^class\x20\K.*?(?=\n\S|\Z)"
 			>
 				<className>
 					<nameExpr expr="\w+(?=\s*[\(|:])" />
 				</className>
 				<function
-					mainExpr="(?&lt;=\sdef\x20).+?(?=:)"
+					mainExpr="\sdef\x20\K.+?(?=:)"
 				>
 					<functionName>
 						<funcNameExpr expr=".*" />
@@ -30,7 +30,7 @@
 				</function>
 			</classRange>
 			<function
-				mainExpr="(?&lt;=\sdef\x20).+?(?=:)"
+				mainExpr="\sdef\x20\K.+?(?=:)"
 			>
 				<functionName>
 					<nameExpr expr=".*" />
diff --git a/PowerEditor/installer/functionList/ruby.xml b/PowerEditor/installer/functionList/ruby.xml
index 14b8e8d1..f901a5b7 100644
--- a/PowerEditor/installer/functionList/ruby.xml
+++ b/PowerEditor/installer/functionList/ruby.xml
@@ -16,7 +16,7 @@
 		>
 			<!-- within a class-->
 			<classRange
-				mainExpr    ="(?&lt;=^class\x20).*?(?=\n\S|\Z)"
+				mainExpr    ="^class\x20\K.*?(?=\n\S|\Z)"
 			>
 				<className>
 					<nameExpr expr="\w+" />
@@ -25,7 +25,7 @@
 					mainExpr="^\s*def\s+\w+"
 				>
 					<functionName>
-						<funcNameExpr expr="(?&lt;=def\s)\w+" />
+						<funcNameExpr expr="def\s\K\w+" />
 					</functionName>
 				</function>
 			</classRange>
@@ -34,7 +34,7 @@
 				mainExpr="^\s*def\s+\w+"
 			>
 				<functionName>
-					<nameExpr expr="(?&lt;=def\s)\w+" />
+					<nameExpr expr="def\s\K\w+" />
 				</functionName>
 			</function>
 		</parser>
diff --git a/scintilla/boostregex/BoostRegExSearch.cxx b/scintilla/boostregex/BoostRegExSearch.cxx
index d4c9641b..40f60c2c 100644
--- a/scintilla/boostregex/BoostRegExSearch.cxx
+++ b/scintilla/boostregex/BoostRegExSearch.cxx
@@ -288,13 +288,8 @@ Sci::Position BoostRegexSearch::FindText(Document* doc, Sci::Position startPosit
 			regex_constants::ECMAScript
 			| (caseSensitive ? 0 : regex_constants::icase);
 		search._regexString = regexString;
-		
-		const bool starts_at_line_start = search.isLineStart(search._startPosition);
-		const bool ends_at_line_end     = search.isLineEnd(search._endPosition);
 		search._boostRegexFlags = 
-			  (starts_at_line_start ? regex_constants::match_default : regex_constants::match_not_bol)
-			| (ends_at_line_end     ? regex_constants::match_default : regex_constants::match_not_eol)
-			| ((sciSearchFlags & SCFIND_REGEXP_DOTMATCHESNL) ? regex_constants::match_default : regex_constants::match_not_dot_newline);
+			((sciSearchFlags & SCFIND_REGEXP_DOTMATCHESNL) ? regex_constants::match_default : regex_constants::match_not_dot_newline);
 		
 		const int empty_match_style = sciSearchFlags & SCFIND_REGEXP_EMPTYMATCH_MASK;
 		const int allow_empty_at_start = sciSearchFlags & SCFIND_REGEXP_EMPTYMATCH_ALLOWATSTART;
@@ -344,15 +339,13 @@ template <class CharT, class CharacterIterator>
 BoostRegexSearch::Match BoostRegexSearch::EncodingDependent<CharT, CharacterIterator>::FindTextForward(SearchParameters& search)
 {
 	CharacterIterator endIterator(search._document, search._endPosition, search._endPosition);
+	CharacterIterator baseIterator(search._document, 0, search._endPosition);
 	Sci::Position next_search_from_position = search._startPosition;
 	bool found = false;
 	bool match_is_valid = false;
 	do {
-		search._boostRegexFlags = search.isLineStart(next_search_from_position)
-			? search._boostRegexFlags & ~regex_constants::match_not_bol
-			: search._boostRegexFlags |  regex_constants::match_not_bol;
 		const bool end_reached = next_search_from_position > search._endPosition;
-		found = !end_reached && boost::regex_search(CharacterIterator(search._document, next_search_from_position, search._endPosition), endIterator, _match, _regex, search._boostRegexFlags);
+		found = !end_reached && boost::regex_search(CharacterIterator(search._document, next_search_from_position, search._endPosition), endIterator, _match, _regex, search._boostRegexFlags, baseIterator);
 		if (found) {
 			const Sci::Position  position = _match[0].first.pos();
 			const Sci::Position  length   = _match[0].second.pos() - position;