5 files changed, 30 insertions, 19 deletions

diff --git a/src/Decoration.cxx b/src/Decoration.cxx
index 5a653a589..0470f26f9 100644
--- a/src/Decoration.cxx
+++ b/src/Decoration.cxx
@@ -90,18 +90,18 @@ void DecorationList::SetCurrentValue(int value) {
 	currentValue = value ? value : 1;
 }
 
-bool DecorationList::FillRange(Sci::Position &position, int value, Sci::Position &fillLength) {
+FillResult<Sci::Position> DecorationList::FillRange(Sci::Position position, int value, Sci::Position fillLength) {
 	if (!current) {
 		current = DecorationFromIndicator(currentIndicator);
 		if (!current) {
 			current = Create(currentIndicator, lengthDocument);
 		}
 	}
-	const bool changed = current->rs.FillRange(position, value, fillLength);
+	const FillResult<Sci::Position> fr = current->rs.FillRange(position, value, fillLength);
 	if (current->Empty()) {
 		Delete(currentIndicator);
 	}
-	return changed;
+	return fr;
 }
 
 void DecorationList::InsertSpace(Sci::Position position, Sci::Position insertLength) {
diff --git a/src/Decoration.h b/src/Decoration.h
index 0d799920e..86397fde1 100644
--- a/src/Decoration.h
+++ b/src/Decoration.h
@@ -51,8 +51,8 @@ public:
 	void SetCurrentValue(int value);
 	int GetCurrentValue() const { return currentValue; }
 
-	// Returns true if some values may have changed
-	bool FillRange(Sci::Position &position, int value, Sci::Position &fillLength);
+	// Returns with changed=true if some values may have changed
+	FillResult<Sci::Position> FillRange(Sci::Position position, int value, Sci::Position fillLength);
 
 	void InsertSpace(Sci::Position position, Sci::Position insertLength);
 	void DeleteRange(Sci::Position position, Sci::Position deleteLength);
diff --git a/src/Document.cxx b/src/Document.cxx
index cb2892c96..e0373a752 100644
--- a/src/Document.cxx
+++ b/src/Document.cxx
@@ -2243,11 +2243,11 @@ void SCI_METHOD Document::DecorationSetCurrentIndicator(int indicator) {
 }
 
 void SCI_METHOD Document::DecorationFillRange(Sci_Position position, int value, Sci_Position fillLength) {
-	Sci::Position sciPosition = static_cast<Sci::Position>(position);
-	Sci::Position sciFillLength = static_cast<Sci::Position>(fillLength);
-	if (decorations.FillRange(sciPosition, value, sciFillLength)) {
+	const FillResult<Sci::Position> fr = decorations.FillRange(
+		static_cast<Sci::Position>(position), value, static_cast<Sci::Position>(fillLength));
+	if (fr.changed) {
 		const DocModification mh(SC_MOD_CHANGEINDICATOR | SC_PERFORMED_USER,
-							sciPosition, sciFillLength);
+							fr.position, fr.fillLength);
 		NotifyModified(mh);
 	}
 }
diff --git a/src/RunStyles.cxx b/src/RunStyles.cxx
index fa8844bfe..03692f673 100644
--- a/src/RunStyles.cxx
+++ b/src/RunStyles.cxx
@@ -126,13 +126,14 @@ DISTANCE RunStyles<DISTANCE, STYLE>::EndRun(DISTANCE position) const {
 }
 
 template <typename DISTANCE, typename STYLE>
-bool RunStyles<DISTANCE, STYLE>::FillRange(DISTANCE &position, STYLE value, DISTANCE &fillLength) {
+FillResult<DISTANCE> RunStyles<DISTANCE, STYLE>::FillRange(DISTANCE position, STYLE value, DISTANCE fillLength) {
+	const FillResult<DISTANCE> resultNoChange{false, position, fillLength};
 	if (fillLength <= 0) {
-		return false;
+		return resultNoChange;
 	}
 	DISTANCE end = position + fillLength;
 	if (end > Length()) {
-		return false;
+		return resultNoChange;
 	}
 	DISTANCE runEnd = RunFromPosition(end);
 	if (styles->ValueAt(runEnd) == value) {
@@ -140,7 +141,7 @@ bool RunStyles<DISTANCE, STYLE>::FillRange(DISTANCE &position, STYLE value, DIST
 		end = starts->PositionFromPartition(runEnd);
 		if (position >= end) {
 			// Whole range is already same as value so no action
-			return false;
+			return resultNoChange;
 		}
 		fillLength = end - position;
 	} else {
@@ -159,6 +160,7 @@ bool RunStyles<DISTANCE, STYLE>::FillRange(DISTANCE &position, STYLE value, DIST
 		}
 	}
 	if (runStart < runEnd) {
+		const FillResult<DISTANCE> result{ true, position, fillLength };
 		styles->SetValueAt(runStart, value);
 		// Remove each old run over the range
 		for (DISTANCE run=runStart+1; run<runEnd; run++) {
@@ -169,16 +171,15 @@ bool RunStyles<DISTANCE, STYLE>::FillRange(DISTANCE &position, STYLE value, DIST
 		RemoveRunIfSameAsPrevious(runStart);
 		runEnd = RunFromPosition(end);
 		RemoveRunIfEmpty(runEnd);
-		return true;
+		return result;
 	} else {
-		return false;
+		return resultNoChange;
 	}
 }
 
 template <typename DISTANCE, typename STYLE>
 void RunStyles<DISTANCE, STYLE>::SetValueAt(DISTANCE position, STYLE value) {
-	DISTANCE len = 1;
-	FillRange(position, value, len);
+	FillRange(position, value, 1);
 }
 
 template <typename DISTANCE, typename STYLE>
diff --git a/src/RunStyles.h b/src/RunStyles.h
index c28621334..af2eb3ec6 100644
--- a/src/RunStyles.h
+++ b/src/RunStyles.h
@@ -12,6 +12,16 @@
 
 namespace Scintilla {
 
+// Return for RunStyles::FillRange reports if anything was changed and the
+// range that was changed. This may be trimmed from the requested range
+// when some of the requested range already had the requested value.
+template <typename DISTANCE>
+struct FillResult {
+	bool changed;
+	DISTANCE position;
+	DISTANCE fillLength;
+};
+
 template <typename DISTANCE, typename STYLE>
 class RunStyles {
 private:
@@ -33,8 +43,8 @@ public:
 	DISTANCE FindNextChange(DISTANCE position, DISTANCE end) const;
 	DISTANCE StartRun(DISTANCE position) const;
 	DISTANCE EndRun(DISTANCE position) const;
-	// Returns true if some values may have changed
-	bool FillRange(DISTANCE &position, STYLE value, DISTANCE &fillLength);
+	// Returns changed=true if some values may have changed
+	FillResult<DISTANCE> FillRange(DISTANCE position, STYLE value, DISTANCE fillLength);
 	void SetValueAt(DISTANCE position, STYLE value);
 	void InsertSpace(DISTANCE position, DISTANCE insertLength);
 	void DeleteAll();