3 files changed, 56 insertions, 0 deletions

diff --git a/src/RunStyles.cxx b/src/RunStyles.cxx
index 9c4e90a66..b74053e75 100644
--- a/src/RunStyles.cxx
+++ b/src/RunStyles.cxx
@@ -9,6 +9,8 @@
 #include <stdlib.h>
 #include <stdarg.h>
 
+#include <stdexcept>
+
 #include "Platform.h"
 
 #include "Scintilla.h"
@@ -113,7 +115,13 @@ int RunStyles::EndRun(int position) {
 }
 
 bool RunStyles::FillRange(int &position, int value, int &fillLength) {
+	if (fillLength <= 0) {
+		throw std::invalid_argument("RunStyles::FillRange <= 0 length.");
+	}
 	int end = position + fillLength;
+	if (end > Length()) {
+		throw std::invalid_argument("RunStyles::FillRange length goes past end.");
+	}
 	int runEnd = RunFromPosition(end);
 	if (styles->ValueAt(runEnd) == value) {
 		// End already has value so trim range.
@@ -249,3 +257,31 @@ int RunStyles::Find(int value, int start) const {
 	}
 	return -1;
 }
+
+void RunStyles::Check() {
+	if (Length() < 0) {
+		throw std::runtime_error("RunStyles: Length can not be negative.");
+	}
+	if (starts->Partitions() < 1) {
+		throw std::runtime_error("RunStyles: Must always have 1 or more partitions.");
+	}
+	if (starts->Partitions() != styles->Length()-1) {
+		throw std::runtime_error("RunStyles: Partitions and styles different lengths.");
+	}
+	int start=0;
+	while (start < Length()) {
+		int end = EndRun(start);
+		if (start >= end) {
+			throw std::runtime_error("RunStyles: Partition is 0 length.");
+		}
+		start = end;
+	}
+	if (styles->ValueAt(styles->Length()-1) != 0) {
+		throw std::runtime_error("RunStyles: Unused style at end changed.");
+	}
+	for (int j=1; j<styles->Length()-1; j++) {
+		if (styles->ValueAt(j) == styles->ValueAt(j-1)) {
+			throw std::runtime_error("RunStyles: Style of a partition same as previous.");
+		}
+	}
+}
diff --git a/src/RunStyles.h b/src/RunStyles.h
index 4e90969a2..521c701fa 100644
--- a/src/RunStyles.h
+++ b/src/RunStyles.h
@@ -43,6 +43,8 @@ public:
 	bool AllSame() const;
 	bool AllSameAs(int value) const;
 	int Find(int value, int start) const;
+
+	void Check();
 };
 
 #ifdef SCI_NAMESPACE
diff --git a/test/unit/testRunStyles.cxx b/test/unit/testRunStyles.cxx
index 8fec25b56..3c09dd87a 100644
--- a/test/unit/testRunStyles.cxx
+++ b/test/unit/testRunStyles.cxx
@@ -2,6 +2,8 @@
 
 #include <string.h>
 
+#include <stdexcept>
+
 #include "Platform.h"
 
 #include "SplitVector.h"
@@ -311,4 +313,20 @@ TEST_F(RunStylesTest, DeleteEndRun) {
 	EXPECT_EQ(1, prs->EndRun(0));
 	EXPECT_EQ(0, prs->StartRun(1));
 	EXPECT_EQ(1, prs->EndRun(1));
+	prs->Check();
+}
+
+TEST_F(RunStylesTest, OutsideBounds) {
+	prs->InsertSpace(0, 1);
+	int startFill = 1;
+	int lengthFill = 1;
+	try {
+		prs->FillRange(startFill, 99, lengthFill);
+	} catch (std::invalid_argument &) {
+		// Exception is supposed to occur so ignore.
+	}
+	EXPECT_EQ(1, prs->Length());
+	EXPECT_EQ(1, prs->Runs());
+	EXPECT_EQ(0, prs->StartRun(0));
+	EXPECT_EQ(1, prs->EndRun(0));
 }