Fix bug #7058 (Crash when invoking CAS on a multiline AMS context)

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/branches/BRANCH_1_6_X@36527 a592a061-630c-0410-9148-cb99ea01b6c8

src/mathed/InsetMathHull.cpp

@@ -53,6 +53,7 @@
 #include "graphics/PreviewImage.h"
 #include "graphics/PreviewLoader.h"
 
+#include "frontends/alert.h"
 #include "frontends/Painter.h"
 
 #include "support/lassert.h"
@@ -1146,6 +1147,15 @@ void InsetMathHull::doExtern(Cursor & cur, FuncRequest & func)
 	//	return;
 	//}
 
+	// only inline, display or eqnarray math is allowed
+	if (getType() > hullEqnArray) {
+		frontend::Alert::warning(_("Bad math environment"),
+				_("Computation cannot be performed for AMS "
+				  "math environments.\nChange the math "
+				  "formula type and try again."));
+		return;
+	}
+
 	MathData eq;
 	eq.push_back(MathAtom(new InsetMathChar('=')));
 

status.16x

@@ -56,6 +56,9 @@ What's new
 
 * USER INTERFACE
 
+- Fix crash when using a computer algebra system from within AMS math
+  environments (bug 7058).
+
 - Fix insertion of a user math macro trough the math-insert lfun when a
   selection is present (bug 6939).