Prevent stripping of format specifiers from -exec commands. (#1277)

src/OpenDebugAD7/AD7DebugSession.cs

@@ -2862,7 +2862,15 @@ protected override void HandleEvaluateRequestAsync(IRequestResponder<EvaluateArg
             {
                 // If this is an -exec command (or starts with '`') treat it as a console command and log telemetry
                 if (expression.StartsWith("-exec", StringComparison.Ordinal) || expression[0] == '`')
+                {
                     isExecInConsole = true;
+                    // Append a sacrificial comma. The purpose of this comma is to be stripped when
+                    // ParseText calls GetVariable which calls VariableInformation which calls
+                    // StripFormatSpecifier. This protects the expression from being modified in
+                    // the case where it looks as if it ends with a format specifier. See issue
+                    // #1277 for details.
+                    expression += ",";
+                }
             }
 
             int hr;