From c19dd24d81de9e853e16a1fdfe38a69c7dee8091 Mon Sep 17 00:00:00 2001
From: zufuliu <zufuliu@gmail.com>
Date: Fri, 2 Feb 2024 18:11:47 +0800
Subject: [PATCH] Fix infinite loop in C# and Nim string interpolating
 highlighting code.

---
 scintilla/lexers/LexCSharp.cxx | 13 +++++++++----
 scintilla/lexers/LexNim.cxx    |  8 ++++++--
 scintilla/lexers/LexPython.cxx |  9 +++------
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/scintilla/lexers/LexCSharp.cxx b/scintilla/lexers/LexCSharp.cxx
index 9bd465cc19..e287acd17a 100644
--- a/scintilla/lexers/LexCSharp.cxx
+++ b/scintilla/lexers/LexCSharp.cxx
@@ -206,6 +206,7 @@ void ColouriseCSharpDoc(Sci_PositionU startPos, Sci_Position lengthDoc, int init
 	int chPrevNonWhite = 0;
 	DocTagState docTagState = DocTagState::None;
 	EscapeSequence escSeq;
+	bool closeBrace = false;
 
 	std::vector<InterpolatedStringState> nestedState;
 
@@ -477,8 +478,10 @@ void ColouriseCSharpDoc(Sci_PositionU startPos, Sci_Position lengthDoc, int init
 		case SCE_CSHARP_RAWSTRING_ML:
 		case SCE_CSHARP_INTERPOLATED_RAWSTRING_ML:
 			if (sc.atLineStart && IsSingleLineString(sc.state)) {
-				sc.SetState(SCE_CSHARP_DEFAULT);
-				break;
+				if (!closeBrace) {
+					sc.SetState(SCE_CSHARP_DEFAULT);
+					break;
+				}
 			}
 			if  (sc.ch == '\\') {
 				if (HasEscapeChar(sc.state)) {
@@ -551,6 +554,7 @@ void ColouriseCSharpDoc(Sci_PositionU startPos, Sci_Position lengthDoc, int init
 						}
 					}
 				} else if (sc.ch == '}') {
+					closeBrace = false;
 					if (IsInterpolatedString(sc.state)) {
 						const int interpolatorCount = IsPlainString(sc.state) ? 1 : GetMatchedDelimiterCount(styler, sc.currentPos, '}');
 						const bool interpolating = !nestedState.empty() && (interpolatorCount >= stringInterpolatorCount);
@@ -702,6 +706,7 @@ void ColouriseCSharpDoc(Sci_PositionU startPos, Sci_Position lengthDoc, int init
 				sc.SetState(SCE_CSHARP_IDENTIFIER);
 			} else if (IsAGraphic(sc.ch) && sc.ch != '\\') {
 				const bool interpolating = !nestedState.empty();
+				sc.SetState(interpolating ? SCE_CSHARP_OPERATOR2 : SCE_CSHARP_OPERATOR);
 				if (sc.ch == '(' || sc.ch == '[') {
 					if (interpolating) {
 						nestedState.back().parenCount += 1;
@@ -724,7 +729,8 @@ void ColouriseCSharpDoc(Sci_PositionU startPos, Sci_Position lengthDoc, int init
 						escSeq.outerState = state.state;
 						stringDelimiterCount = state.delimiterCount;
 						stringInterpolatorCount = state.interpolatorCount;
-						sc.SetState((sc.ch == '}') ? state.state : SCE_CSHARP_FORMAT_SPECIFIER);
+						closeBrace = sc.ch == '}';
+						sc.ChangeState(closeBrace ? state.state : SCE_CSHARP_FORMAT_SPECIFIER);
 						continue;
 					}
 				} else {
@@ -736,7 +742,6 @@ void ColouriseCSharpDoc(Sci_PositionU startPos, Sci_Position lengthDoc, int init
 						kwType = KeywordType::None;
 					}
 				}
-				sc.SetState(interpolating ? SCE_CSHARP_OPERATOR2 : SCE_CSHARP_OPERATOR);
 			}
 		}
 
diff --git a/scintilla/lexers/LexNim.cxx b/scintilla/lexers/LexNim.cxx
index 8c8172948b..8df38a5b67 100644
--- a/scintilla/lexers/LexNim.cxx
+++ b/scintilla/lexers/LexNim.cxx
@@ -237,8 +237,12 @@ void ColouriseNimDoc(Sci_PositionU startPos, Sci_Position lengthDoc, int initSty
 		case SCE_NIM_TRIPLE_STRING:
 		case SCE_NIM_TRIPLE_FMTSTRING:
 			if (sc.atLineStart && sc.state < SCE_NIM_TRIPLE_STRING) {
-				sc.SetState(SCE_NIM_DEFAULT);
-			} else if (sc.ch == '\\') {
+				if (fmtPart == FormatStringPart::None) {
+					sc.SetState(SCE_NIM_DEFAULT);
+					break;
+				}
+			}
+			if (sc.ch == '\\') {
 				if (sc.state <= SCE_NIM_FMTSTRING) {
 					escSeq.resetEscapeState(sc.state, sc.chNext);
 					sc.SetState(SCE_NIM_ESCAPECHAR);
diff --git a/scintilla/lexers/LexPython.cxx b/scintilla/lexers/LexPython.cxx
index dd57f1c8b9..be70b9b94f 100644
--- a/scintilla/lexers/LexPython.cxx
+++ b/scintilla/lexers/LexPython.cxx
@@ -785,7 +785,9 @@ void ColourisePyDoc(Sci_PositionU startPos, Sci_Position lengthDoc, int initStyl
 					sc.SetState(SCE_PY_OPERATOR);
 				}
 			} else if (IsAGraphic(sc.ch) && sc.ch != '\\') {
+				kwType = KeywordType::None;
 				const bool interpolating = !nestedState.empty();
+				sc.SetState(interpolating ? SCE_PY_OPERATOR2 : SCE_PY_OPERATOR);
 				int braceCount = 0;
 				if (sc.ch == '{' || sc.ch == '[' || sc.ch == '(') {
 					if (interpolating) {
@@ -809,19 +811,14 @@ void ColourisePyDoc(Sci_PositionU startPos, Sci_Position lengthDoc, int initStyl
 						}
 					}
 				}
-
-				int style = SCE_PY_OPERATOR;
 				if (interpolating) {
-					style = SCE_PY_OPERATOR2;
 					const FormattedStringState &state = nestedState.back();
 					if (state.parenCount == 0 && IsPyFormattedStringEnd(sc, braceCount)) {
 						fstringPart = (sc.ch == '}') ? FormattedStringPart::End : FormattedStringPart::FormatSpec;
-						sc.SetState(state.state);
+						sc.ChangeState(state.state);
 						continue;
 					}
 				}
-				sc.SetState(style);
-				kwType = KeywordType::None;
 			}
 		}