Patch: validate for MathCasesInset

[Dekel Tsur]

This patch make lyx add \usepackage{amsmath} if \begin{cases}
is used inside a math formula.

Index: math_casesinset.C
===================================================================
RCS file: /usr/local/lyx/cvsroot/lyx-devel/src/mathed/math_casesinset.C,v
retrieving revision 1.11
diff -u -p -r1.11 math_casesinset.C
--- math_casesinset.C   11 Jul 2002 11:27:24 -0000      1.11
+++ math_casesinset.C   25 Oct 2002 21:08:55 -0000
@@ -8,6 +8,7 @@
 #include "math_parser.h"
 #include "math_mathmlstream.h"
 #include "math_support.h"
+#include "LaTeXFeatures.h"
 #include "support/LOstream.h"
 
 
@@ -67,4 +68,10 @@ void MathCasesInset::maplize(MapleStream
 void MathCasesInset::infoize(std::ostream & os) const
 {
        os << "Cases ";
+}
+
+
+void MathCasesInset::validate(LaTeXFeatures & features) const
+{
+               features.require("amsmath");
 }
Index: math_casesinset.h
===================================================================
RCS file: /usr/local/lyx/cvsroot/lyx-devel/src/mathed/math_casesinset.h,v
retrieving revision 1.4
diff -u -p -r1.4 math_casesinset.h
--- math_casesinset.h   8 Jul 2002 16:20:53 -0000       1.4
+++ math_casesinset.h   25 Oct 2002 21:08:55 -0000
@@ -28,6 +28,8 @@ public:
        void maplize(MapleStream &) const;
        ///
        void write(WriteStream & os) const;
+       ///
+       void validate(LaTeXFeatures & features) const;
 };
 
 #endif