Backported bug 108258.
diff --git a/org.eclipse.jface.text/projection/org/eclipse/jface/text/source/projection/ProjectionViewer.java b/org.eclipse.jface.text/projection/org/eclipse/jface/text/source/projection/ProjectionViewer.java
index f8b5af3..77589db 100644
--- a/org.eclipse.jface.text/projection/org/eclipse/jface/text/source/projection/ProjectionViewer.java
+++ b/org.eclipse.jface.text/projection/org/eclipse/jface/text/source/projection/ProjectionViewer.java
@@ -611,6 +611,11 @@
} else {
try {
fHandleProjectionChanges= false;
+ // https://bugs.eclipse.org/bugs/show_bug.cgi?id=108258
+ // make sure the document range is strictly line based
+ int end= offset + length;
+ offset= toLineStart(projection.getMasterDocument(), offset, false);
+ length= toLineStart(projection.getMasterDocument(), end, true) - offset;
projection.addMasterDocumentRange(offset, length);
} finally {
fHandleProjectionChanges= true;
@@ -636,12 +641,38 @@
} else {
try {
fHandleProjectionChanges= false;
+ // https://bugs.eclipse.org/bugs/show_bug.cgi?id=108258
+ // make sure the document range is strictly line based
+ int end= offset + length;
+ offset= toLineStart(projection.getMasterDocument(), offset, false);
+ length= toLineStart(projection.getMasterDocument(), end, true) - offset;
projection.removeMasterDocumentRange(offset, length);
} finally {
fHandleProjectionChanges= true;
}
}
}
+
+ /**
+ * Returns the first line offset <= <code>offset</code>. If <code>testLastLine</code>
+ * is <code>true</code> and the offset is on last line then <code>offset</code> is returned.
+ *
+ * @param document the document
+ * @param offset the master document offset
+ * @param testLastLine <code>true</code> if the test for the last line should be performed
+ * @return the closest line offset >= <code>offset</code>
+ * @throws BadLocationException if the offset is invalid
+ * @since 3.2
+ */
+ private int toLineStart(IDocument document, int offset, boolean testLastLine) throws BadLocationException {
+ if (document == null)
+ return offset;
+
+ if (testLastLine && offset >= document.getLineInformationOfOffset(document.getLength() - 1).getOffset())
+ return offset;
+
+ return document.getLineInformationOfOffset(offset).getOffset();
+ }
/*
* @see org.eclipse.jface.text.TextViewer#setVisibleRegion(int, int)
