* Commit that added line was fixing something unrelated; deduced line was duplicated in merge resolution. * Line was comparing two different enums for equality

* Commit that added line was fixing something unrelated; deduced line was duplicated in merge resolution. * Line was comparing two different enums for equality and failing; commit history showed one enum had been an int and the commit message that changed it explained why the author thought the comparison was safe anyway, so we could ask why that wasn't true Plus even when the _cause_ is in the code, I constantly check "what's the history of this function?" while trying to figure out whether the code was always intended to do this crazy thing or whether it's been morphed by recent changes. I have "Show selection history" mapped to Ctrl+Shift+G+H in PyCharm.