From 4bb427a2443d64bd01aad66ebdc0b3f802546bae Mon Sep 17 00:00:00 2001
From: Kornel Benko <kornel@lyx.org>
Date: Sun, 8 May 2022 14:30:45 +0200
Subject: [PATCH] FindAdv: Amend 627cd6de: Use '~' instead of "\\ " for search
 if possible

Also fix a thinko in interpreting the found values.
The match_len describes the length of the second regex field,
while matchend is the length of the search field 0.
---
 src/insets/InsetSpace.cpp |  5 ++++-
 src/lyxfind.cpp           | 11 +++++------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/insets/InsetSpace.cpp b/src/insets/InsetSpace.cpp
index 92d4c43609..669239b55f 100644
--- a/src/insets/InsetSpace.cpp
+++ b/src/insets/InsetSpace.cpp
@@ -579,7 +579,10 @@ void InsetSpace::latex(otexstream & os, OutputParams const & runparams) const
 {
 	switch (params_.kind) {
 	case InsetSpaceParams::NORMAL:
-		os << (runparams.free_spacing && (runparams.for_search == OutputParams::NoSearch) ? " " : "\\ ");
+		if (runparams.for_search != OutputParams::NoSearch)
+			os << "~";
+		else
+			os << (runparams.free_spacing ? " " : "\\ ");
 		break;
 	case InsetSpaceParams::PROTECTED:
 		if (runparams.local_font &&
diff --git a/src/lyxfind.cpp b/src/lyxfind.cpp
index 83ccb23824..669742e5e2 100644
--- a/src/lyxfind.cpp
+++ b/src/lyxfind.cpp
@@ -831,10 +831,6 @@ string string2regex(string in)
 			blanks++;
 			i++;
 		}
-		else if (tempx[i] == '\\' && tempx[i+1] == '\\' && tempx[i+2] == ' ') {
-			blanks++;
-			i += 2;
-		}
 		else {
 			if (blanks > 0) {
 				temp += "\\s+";
@@ -3740,6 +3736,9 @@ MatchResult MatchStringAdv::findAux(DocIterator const & cur, int len, bool at_be
 		if (lng != str.size()) {
 			str = str.substr(0, lng);
 		}
+		// Replace occurences of '~' to ' '
+		static std::regex specialChars { R"(~)" };
+		str = std::regex_replace(str, specialChars,  R"( )" );
 	}
 	if (str.empty()) {
 		mres.match_len = -1;
@@ -3808,7 +3807,7 @@ MatchResult MatchStringAdv::findAux(DocIterator const & cur, int len, bool at_be
 			while (mres.match_len > 0) {
 				QChar c = qstr.at(matchend - 1);
 				if ((c == '\n') || (c == '}') || (c == '{')) {
-					mres.match_len--;
+					// mres.match_len--;
 					matchend--;
 				}
 				else
@@ -3837,7 +3836,7 @@ MatchResult MatchStringAdv::findAux(DocIterator const & cur, int len, bool at_be
 			while (mres.match_len > 0) {
 				char c = str.at(matchend - 1);
 				if ((c == '\n') || (c == '}') || (c == '{')) {
-					mres.match_len--;
+					// mres.match_len--;
 					matchend--;
 				}
 				else
-- 
2.39.2