diff --git a/src/apps/debugger/files/SourceFile.cpp b/src/apps/debugger/files/SourceFile.cpp
index b5ff5f1957..479c0141b2 100644
--- a/src/apps/debugger/files/SourceFile.cpp
+++ b/src/apps/debugger/files/SourceFile.cpp
@@ -88,15 +88,12 @@ SourceFile::Init(const char* path)
 	fFileContent[fileSize] = '\0';
 
 	// count lines
-	fLineCount = 0;
+	fLineCount = 1;
 	for (size_t i = 0; i < fileSize; i++) {
 		if (fFileContent[i] == '\n')
 			fLineCount++;
 	}
 
-	if (fFileContent[fileSize - 1] != '\n')
-		fLineCount++;
-
 	// allocate line offset array
 	fLineOffsets = new(std::nothrow) int32[fLineCount + 1];
 	if (fLineOffsets == NULL)
@@ -111,7 +108,7 @@ SourceFile::Init(const char* path)
 			fLineOffsets[lineIndex++] = i + 1;
 		}
 	}
-	fLineOffsets[fLineCount] = fileSize - 1;
+	fLineOffsets[fLineCount] = fileSize + 1;
 
 	return B_OK;
 }
diff --git a/src/apps/debugger/gui/team_window/SourceView.cpp b/src/apps/debugger/gui/team_window/SourceView.cpp
index 79f9c16cc5..81ef39702c 100644
--- a/src/apps/debugger/gui/team_window/SourceView.cpp
+++ b/src/apps/debugger/gui/team_window/SourceView.cpp
@@ -261,6 +261,7 @@ private:
 			SelectionPoint		fSelectionStart;
 			SelectionPoint		fSelectionEnd;
 			SelectionPoint		fSelectionBase;
+			SelectionPoint		fLastClickPoint;
 			bigtime_t			fLastClickTime;
 			int16				fClickCount;
 			rgb_color			fTextColor;
@@ -856,6 +857,7 @@ SourceView::TextView::TextView(SourceView* sourceView, FontInfo* fontInfo)
 	fSelectionStart(-1, -1),
 	fSelectionEnd(-1, -1),
 	fSelectionBase(-1, -1),
+	fLastClickPoint(-1, -1),
 	fLastClickTime(0),
 	fClickCount(0),
 	fSelectionMode(false),
@@ -1009,6 +1011,7 @@ SourceView::TextView::MouseDown(BPoint where)
 		_GetSelectionRegion(region);
 		bigtime_t clickTime = system_time();
 		SelectionPoint point = _SelectionPointAt(where);
+		fLastClickPoint = point;
 		bigtime_t clickSpeed = 0;
 		get_click_speed(&clickSpeed);
 		if (clickTime - fLastClickTime < clickSpeed
@@ -1104,6 +1107,16 @@ void
 SourceView::TextView::MouseUp(BPoint where)
 {
 	fSelectionMode = false;
+	if (fTrackState == kTracking && fClickCount < 2) {
+		
+		// if we clicked without dragging or double/triple clicking,
+		// clear the current selection (if any)
+		SelectionPoint point = _SelectionPointAt(where);
+		if (fLastClickPoint == point) {
+			fSelectionBase = fSelectionStart = fSelectionEnd;
+			Invalidate();
+		}
+	}
 	fTrackState = kNotTracking;
 }