* InsetMathHull (numbered):

- prevent NULL pointer (bug 5688).

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/branches/BRANCH_1_6_X@28320 a592a061-630c-0410-9148-cb99ea01b6c8

src/mathed/InsetMathHull.cpp

@@ -530,6 +530,11 @@ void InsetMathHull::numbered(row_type row, bool num)
 		label_[row] = 0;
 		// We need an update of the Buffer reference cache.
 		// This is achieved by updateLabels().
+		if (!buffer_) {
+			// The buffer is set at the end of readInset
+			// when parsing the inset, buffer_ is 0.
+			return;
+		}
 		lyx::updateLabels(buffer());
 	}
 }