[Gambas-user] Issue 93 in gambas: Error backtrace not always correct

[gambas at ...2524...]

Status: New
Owner: ----
Labels: Version Type-Bug Priority-Medium OpSys-Any Dist-Any Arch-Any  
Desktop-Any GUI-Any

New issue 93 by emil.len... at ...626...: Error backtrace not always correct
http://code.google.com/p/gambas/issues/detail?id=93

1) Describe the problem.
The backtrace that can be obtained by Error.Backtrace does not always  
contain the correct backtrace. That backtrace seems to be the current stack  
(not as it looked liked when the error occurred), but the frames with a  
greater depth than the current depth are not popped off (so if no functions  
are called between the error and the Error.Backtrace, everything will be  
ok).
See example below.

2) GIVE THE FOLLOWING INFORMATIONS (if they are appropriate):

Version: TRUNK
Revision: r4063
Operating system: Linux
Architecture: x86_64

3) Provide a little project that reproduces the bug or the crash.
Public Sub PrintBacktrace()
   Dim s As String
   For Each s In Error.Backtrace
     Print s
   Next
End
Public Sub PrintErr()
   Print "An error occurred: "; Error.Text
   PrintBacktrace() 'Line 9
End
Public Function Divide(a As Integer, b As Integer) As Integer
   Return a / b 'Line 12
End
Public Sub run()
   Print Divide(1, 0) 'Line 15
End
Public Sub Main()
   run() 'Line 18
   Catch
     PrintErr() 'Line 20
End

This will print:
An error occurred: Division by zero
MMain.Divide.12
MMain.PrintErr.9
MMain.Main.20

While it should be:
An error occurred: Division by zero
MMain.Divide.12
MMain.run.15
MMain.Main.18

The current backtrace-information (stack) should be copied when an error  
occurs, not during Error.Backtrace, like it is currently.


4) If your project needs a database, try to provide it, or part of it.

5) Explain clearly how to reproduce the bug or the crash.
Run the example.

6) By doing that carefully, you have done 50% of the bug fix job!