Hopefully fix the profiler right. Add a test suite that checks that

it deals correctly with some anomalous cases; according to this test
suite I've fixed it right.

The anomalous cases had to do with 'exception' events: these aren't
generated when they would be most helpful, and the profiler has to
work hard to recover the right information.  The problems occur when C
code (such as hasattr(), which is used as the example here) calls back
into Python code and clears an exception raised by that Python code.
Consider this example:

    def foo():
        hasattr(obj, "bar")

Where obj is an instance from a class like this:

    class C:
        def __getattr__(self, name):
            raise AttributeError

The profiler sees the following sequence of events:

    call (foo)
    call (__getattr__)
    exception (in __getattr__)
    return (from foo)

Previously, the profiler would assume the return event returned from
__getattr__. An if statement checking for this condition and raising
an exception was commented out...  This version does the right thing.

1 files changed, 17 insertions, 0 deletions

diff --git a/Lib/test/output/test_profile b/Lib/test/output/test_profile
new file mode 100644
index 0000000..b36a016
--- /dev/null
+++ b/Lib/test/output/test_profile
@@ -0,0 +1,17 @@
+test_profile
+         53 function calls in 1.000 CPU seconds
+
+   Ordered by: standard name
+
+   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
+        1    0.000    0.000    1.000    1.000 <string>:1(?)
+        0    0.000             0.000          profile:0(profiler)
+        1    0.000    0.000    1.000    1.000 profile:0(testfunc())
+        1    0.400    0.400    1.000    1.000 test_profile.py:21(testfunc)
+        2    0.080    0.040    0.600    0.300 test_profile.py:30(helper)
+        4    0.116    0.029    0.120    0.030 test_profile.py:48(helper1)
+        8    0.312    0.039    0.400    0.050 test_profile.py:56(helper2)
+        8    0.064    0.008    0.080    0.010 test_profile.py:66(subhelper)
+       28    0.028    0.001    0.028    0.001 test_profile.py:78(__getattr__)
+
+