config: make config.items() return a copy config.items() was iterating over a copy of the data for the the specified section on Python 2 by using .items(). However, on Python 3, items() does not make a copy, so let's switch to explicitly making a copy to make it safe on both Python 2 and Python 3.

filemerge: store error messages in module variables Copytracing may be disabled because it's too slow (see experimental.disablecopytrace config option). In that case user may get errors like 'local changed FILE which other deleted'. It would be nice to give user a hint to rerun command with `--config experimental.disablecopytrace=False`. To make it possible let's extract error message to variables so that extension may overwrite them.

run-tests: support multiple cases in .t test Sometimes we want to run similar tests with slightly different configurations. Previously we duplicate the test files. This patch introduces special "#testcases" syntax that allows a single .t file to contain multiple test cases. Defined cases could be tested using "#if". For example, if a test should behave the same with or without an experimental flag, we can add the following to the .t header: #testcases default experimental-a #if experimental-a $ cat >> $HGRCPATH << EOF > [experimental] > feature=a > EOF #endif The "experimental-a" block won't be executed when running the "default" test case.