Bug [#2260]. Fix bug with SCI_GETLASTCHILD when lParam is -1.

Fixed cast on SCI_FOLDCHILDREN to use correct type.

4 files changed, 23 insertions, 5 deletions

diff --git a/doc/ScintillaHistory.html b/doc/ScintillaHistory.html
index 6ef9b2b66..411714498 100644
--- a/doc/ScintillaHistory.html
+++ b/doc/ScintillaHistory.html
@@ -574,6 +574,18 @@
     </ul>
     <h2>Releases</h2>
     <h3>
+       <a href="https://www.scintilla.org/scintilla504.zip">Release 5.0.4</a>
+    </h3>
+    <ul>
+	<li>
+	Released 2 June 2021.
+	</li>
+	<li>
+	Fixed bug with SCI_GETLASTCHILD.
+	<a href="https://sourceforge.net/p/scintilla/bugs/2260/">Bug #2260</a>.
+	</li>
+    </ul>
+    <h3>
        <a href="https://www.scintilla.org/scintilla503.zip">Release 5.0.3</a>
     </h3>
     <ul>
diff --git a/src/Document.cxx b/src/Document.cxx
index 74701bd8c..6531ad264 100644
--- a/src/Document.cxx
+++ b/src/Document.cxx
@@ -525,14 +525,13 @@ static bool IsSubordinate(FoldLevel levelStart, FoldLevel levelTry) noexcept {
 }
 
 Sci::Line Document::GetLastChild(Sci::Line lineParent, std::optional<FoldLevel> level, Sci::Line lastLine) {
-	if (!level)
-		level = LevelNumberPart(GetFoldLevel(lineParent));
+	const FoldLevel levelStart = level.value_or(LevelNumberPart(GetFoldLevel(lineParent)));
 	const Sci::Line maxLine = LinesTotal();
 	const Sci::Line lookLastLine = (lastLine != -1) ? std::min(LinesTotal() - 1, lastLine) : -1;
 	Sci::Line lineMaxSubord = lineParent;
 	while (lineMaxSubord < maxLine - 1) {
 		EnsureStyledTo(LineStart(lineMaxSubord + 2));
-		if (!IsSubordinate(*level, GetFoldLevel(lineMaxSubord + 1)))
+		if (!IsSubordinate(levelStart, GetFoldLevel(lineMaxSubord + 1)))
 			break;
 		if ((lookLastLine != -1) && (lineMaxSubord >= lookLastLine) && !LevelIsWhitespace(GetFoldLevel(lineMaxSubord)))
 			break;
diff --git a/src/Editor.cxx b/src/Editor.cxx
index e208260ab..f59eb5785 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -7363,7 +7363,7 @@ sptr_t Editor::WndProc(Message iMessage, uptr_t wParam, sptr_t lParam) {
 		return pdoc->GetLevel(static_cast<Sci::Line>(wParam));
 
 	case Message::GetLastChild:
-		return pdoc->GetLastChild(static_cast<Sci::Line>(wParam), static_cast<FoldLevel>(lParam));
+		return pdoc->GetLastChild(static_cast<Sci::Line>(wParam), OptionalFoldLevel(lParam));
 
 	case Message::GetFoldParent:
 		return pdoc->GetFoldParent(static_cast<Sci::Line>(wParam));
@@ -7436,7 +7436,7 @@ sptr_t Editor::WndProc(Message iMessage, uptr_t wParam, sptr_t lParam) {
 		break;
 
 	case Message::FoldChildren:
-		FoldExpand(static_cast<Sci::Line>(wParam), static_cast<FoldAction>(lParam), pdoc->GetFoldLevel(static_cast<int>(wParam)));
+		FoldExpand(static_cast<Sci::Line>(wParam), static_cast<FoldAction>(lParam), pdoc->GetFoldLevel(static_cast<Sci::Line>(wParam)));
 		break;
 
 	case Message::FoldAll:
diff --git a/src/Editor.h b/src/Editor.h
index 08e7d134b..9af2add43 100644
--- a/src/Editor.h
+++ b/src/Editor.h
@@ -624,6 +624,13 @@ protected:	// ScintillaBase subclass needs access to much of Editor
 		return static_cast<const char *>(PtrFromUPtr(wParam));
 	}
 
+	constexpr std::optional<FoldLevel> OptionalFoldLevel(Scintilla::sptr_t lParam) {
+		if (lParam >= 0) {
+			return static_cast<FoldLevel>(lParam);
+		}
+		return std::nullopt;
+	}
+
 	static Scintilla::sptr_t StringResult(Scintilla::sptr_t lParam, const char *val) noexcept;
 	static Scintilla::sptr_t BytesResult(Scintilla::sptr_t lParam, const unsigned char *val, size_t len) noexcept;