Fixed bugs: 140591: [typing] IndexOutOfBoundsException when inserting string literatl at beginning of document

1 files changed, 33 insertions, 1 deletions

diff --git a/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/texteditor/SourceViewerDecorationSupport.java b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/texteditor/SourceViewerDecorationSupport.java
index e8271e975a0..c6b4eda196e 100644
--- a/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/texteditor/SourceViewerDecorationSupport.java
+++ b/org.eclipse.ui.workbench.texteditor/src/org/eclipse/ui/texteditor/SourceViewerDecorationSupport.java
@@ -172,7 +172,39 @@ public class SourceViewerDecorationSupport {
 				gc.drawLine(x1, y1, x1, left.y + textWidget.getLineHeight(offset) - 1);
 
 			} else {
-				textWidget.redrawRange(offset, length + 1, true);
+				/*
+				 * The length for IBeam's is always 0, which causes no redraw to occur in
+				 * StyledText#redraw(int, int, boolean). We try to normally redraw at length of one,
+				 * and up to the line start of the next line if offset is at the end of line. If at
+				 * the end of the document, we redraw the entire document as the offset is behind
+				 * any content.
+				 */
+				final int contentLength= textWidget.getCharCount();
+				if (offset >= contentLength) {
+					textWidget.redraw();
+					return;
+				}
+				
+				char ch= textWidget.getTextRange(offset, 1).charAt(0);
+				if (ch == '\r' || ch == '\n') {
+					// at the end of a line, redraw up to the next line start
+					int nextLine= textWidget.getLineAtOffset(offset) + 1;
+					if (nextLine >= textWidget.getLineCount()) {
+						/*
+						 * Panic code: should not happen, as offset is not the last offset,
+						 * and there is a delimiter character at offset.
+						 */
+						textWidget.redraw();
+						return;
+					}
+					
+					int nextLineOffset= textWidget.getOffsetAtLine(nextLine);
+					length= nextLineOffset - offset;
+				} else {
+					length= 1;
+				}
+				
+				textWidget.redrawRange(offset, length, true);
 			}
 		}
 	}