CID#736166 unlikely out of bounds

Change-Id: I8a0f97be1723766df9f8fe287417365febf54966

basic/source/comp/symtbl.cxx

@@ -350,7 +350,10 @@ void SbiSymDef::SetType( SbxDataType t )
             unsigned char c = (unsigned char)ch2;
             if( c > 0 && c < 128 )
             {
-                t = pIn->pParser->eDefTypes[ ch2 - 'A' ];
+                int nIndex = ch2 - 'A';
+                assert(nIndex >= 0 && nIndex < N_DEF_TYPES);
+                if (nIndex >= 0 && nIndex < N_DEF_TYPES)
+                    t = pIn->pParser->eDefTypes[nIndex];
             }
         }
     }

basic/source/inc/parser.hxx

@@ -77,7 +77,8 @@ public:
     bool          bClassModule;     // true: OPTION ClassModule
     StringVector  aIfaceVector;     // Holds all interfaces implemented by a class module
     StringVector  aRequiredTypes;   // Types used in Dim As New <type> outside subs
-    SbxDataType   eDefTypes[26];    // DEFxxx data types
+#   define N_DEF_TYPES 26
+    SbxDataType   eDefTypes[N_DEF_TYPES];    // DEFxxx data types
 
     SbiParser( StarBASIC*, SbModule* );
     bool Parse();