backport r37288:

Author: baum
	Date: Fri Jan 21 20:18:27 2011
	New Revision: 37288
	URL: http://www.lyx.org/trac/changeset/37288

	Log:
	Fix bug #7252

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/branches/BRANCH_1_6_X@37792 a592a061-630c-0410-9148-cb99ea01b6c8

src/mathed/InsetMathOverset.cpp

@@ -74,6 +74,8 @@ bool InsetMathOverset::idxLast(Cursor & cur) const
 void InsetMathOverset::write(WriteStream & os) const
 {
 	MathEnsurer ensurer(os);
+	if (os.fragile())
+		os << "\\protect";
 	os << "\\overset{" << cell(0) << "}{" << cell(1) << '}';
 }
 

src/mathed/InsetMathUnderset.cpp

@@ -85,6 +85,8 @@ bool InsetMathUnderset::idxUpDown(Cursor & cur, bool up) const
 void InsetMathUnderset::write(WriteStream & os) const
 {
 	MathEnsurer ensurer(os);
+	if (os.fragile())
+		os << "\\protect";
 	os << "\\underset{" << cell(0) << "}{" << cell(1) << '}';
 }
 

status.16x

@@ -56,7 +56,8 @@ What's new
 
 * DOCUMENT INPUT/OUTPUT
 
-
+- Protect the math commands \overset and \underset in fragile context
+  (bug 7252).
 
 
 * USER INTERFACE