Description Kaloyan Raev 2006-05-10 10:03:39 EDT

Problem: 
When debugging JSP file that includes another JSP file, the debugger does not switch the JSP editors when the execution flow goes from the one JSP to the another. 

How to reproduce:  
1. Make a web project (zip attached) with two JSPs: foo.jsp and bar.jsp. foo.jsp includes bar.jsp. 
2. Put breakpoint on the following places: 
  2.1. foo.jsp, line 4
  2.2. bar.jsp, line 4
3. request foo.jsp, ex. http://<host>:<port>/debug/foo.jsp
4. the execution stops on the breakpoint at foo.jsp, line 4. The stack trace in the Debug view and the debugger pointer in the JSP editor show the correct data. 
5. press F8 (resume) to advance to the next breakpoint. 
6. the execution stops on the breakpoint at bar.jsp, line 4. The stack trace in the Debug view correctly shows bar.jsp:4, but the JSP editor still shows foo.jsp and the debugger pointer is at line 4, but in foo.jsp instead of bar.jsp (see attached screenshot). 

Analysis: 
When suspending the execution flow, the stack frames in the Debug view are recomputed. This invokes the JDIStackFrame.bind() method for the stack frame representing the top of the stack - where our breakpoint is. When the execution goes from code in foo.jsp to code in bar.jsp, it is attempted the same stack frame to be updated with the new source code location. The check in on line 151 in JDIStackFrame allows this: 

  if (location.method().equals(fLocation.method())) {
    ...
  }
    
This is because the fMethod in the new and old location is one and the same: "_jspService". The result is that the same stack frame object is reused for the new source file. And when StackFrameSourceDisplayAdapter.displaySource():152 is called it is seen that the stack frame object is the old one and re-lookup of the source locator is not scheduled, which results in not switching the JSP editor. 

Solution: 
One possible solution is to extend the check mentioned above in JDIStackFrame.bind():151 like this: 

  if (location.sourceName().equals(fLocation.sourceName()) && 
      location.method().equals(fLocation.method())) {
    ...
  }

Note that in addition to the method comparision, it is the sourceName compared, too. In our case the sourceName of the old location is "foo.jsp" and for the new one - "bar.jsp". This forces new stack frame object for the new location which later forces the source locator to be re-looked up. 

Patch with the described solution is attached.