Issue #10990: Prevent tests from clobbering a set trace function.
Many tests simply didn't care if they unset a pre-existing trace function. This
made test coverage impossible. This patch fixes various tests to put back any
pre-existing trace function. It also introduces test.support.no_tracing as a
decorator which will temporarily unset the trace function for tests which
simply fail otherwise.
Thanks to Kristian Vlaardingerbroek for helping to find the cause of various
trace function unsets.
diff --git a/Lib/doctest.py b/Lib/doctest.py
index b79db17..e8f3bcb 100644
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -1373,6 +1373,7 @@
# Note that the interactive output will go to *our*
# save_stdout, even if that's not the real sys.stdout; this
# allows us to write test cases for the set_trace behavior.
+ save_trace = sys.gettrace()
save_set_trace = pdb.set_trace
self.debugger = _OutputRedirectingPdb(save_stdout)
self.debugger.reset()
@@ -1392,6 +1393,7 @@
finally:
sys.stdout = save_stdout
pdb.set_trace = save_set_trace
+ sys.settrace(save_trace)
linecache.getlines = self.save_linecache_getlines
sys.displayhook = save_displayhook
if clear_globs: