[Mono-bugs] [Bug 70400][Min] New - Wrong behavior of breaking out of SWITCH, when done from within a nested SWITCH and a nested IF

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Changed by vgapeyev@cis.upenn.edu.

http://bugzilla.ximian.com/show_bug.cgi?id=70400

--- shadow/70400	2004-12-09 17:42:10.000000000 -0500
+++ shadow/70400.tmp.26519	2004-12-09 17:42:10.000000000 -0500
@@ -0,0 +1,90 @@
+Bug#: 70400
+Product: Mono: Compilers
+Version: 1.0
+OS: 
+OS Details: Mandrake 10.0
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Minor
+Component: C#
+AssignedTo: mono-bugs@ximian.com                            
+ReportedBy: vgapeyev@cis.upenn.edu               
+QAContact: mono-bugs@ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: Wrong behavior of breaking out of SWITCH, when done from within a nested SWITCH and a nested IF
+
+Description of Problem:
+
+Suppose there is a SWITCH, with a nested SWITCH, with a nested IF.  If
+there is a BREAK inside IF, it should switch the control into the
+inner SWITCH, but it jumps into the outer SWITCH.
+
+To reproduce the bug, the condition in the IF must be computable,
+(rather than a constant which probably gets optimized away).
+
+
+Steps to reproduce the problem:
+Compile and run this (mono 1.0.5): 
+
+using C = System.Console;
+
+class Test  {
+    
+    public static void Main (string[] args) {
+      switch (1) {
+        default:
+          switch (2) {
+            default:
+              int flag = 1;       //makes the next if computable -- essential!
+	      if (flag == 1) {
+		C.WriteLine("**** This one is expected");
+                break;  //break-2
+	      }  
+              else  goto lbl;
+          }
+	  break;  //break-1  This point is REACHABLE through break-2, 
+	          // contrary to the warning from compiler!
+        
+        lbl:
+          C.WriteLine("**** THIS SHOULD NOT APPEAR, since break-1 was
+supposed to fire ***");
+          break;
+        
+      }
+    }
+}
+  
+
+
+Actual Results:
+
+% mcs simple.cs
+simple.cs(17) warning CS0162: Unreachable code detected
+Compilation succeeded - 1 warning(s)
+% mono simple.exe
+**** This one is expected
+**** THIS SHOULD NOT APPEAR, since break-1 was supposed to fire ***
+
+
+Expected Results:
+
+The last line of the output should not appear. 
+
+The compiler warning should not appear, since the corresponding point
+IS reachable, as explained in the Description above.
+
+
+How often does this happen? 
+
+Completely reproducible.
+
+
+Additional Information:
+
+This bug is probably the same as #59867.  I have just noticed that the
+latter was marked as RESOLVED FIXED, so I re-raise it here.  The code
+reported in #5986 still fails to work correctly with mono/mcs 1.0.5,
+but the sample above is a little shorter.