Subject: bug#22301: 25.1.50; Emacs crashes while lisp debugging

From: Nicolas Richard <[email-masked]>
Date: Wed, 20 Jan 2016 16:30:27 +0100

> automatic commit there is an incredible number of files affected. I
> don't know why that happened so... I hope I did not make anything too
> hard to revert if need be.

IIUC you're talking about the merge commit you created, namely
b895c72059521fec064ff27b4cfcfa4104081c4e.

What you did is that you were on your local branch, with your SES
changes, then you git pull'd from savannah/master which created a merge
commit (and then pushed the result). When creating a merge commit, emacs
uses current commit as first parent, and the second parent is the commit
at the tip of the other branch (in your case savannah/master).

Now the trick is that "git diff" will show the diff wrt the *first*
parent. In this case, git diff thus shows a diff between the merged
state and the first parent, which is your own commit. IOW, it doesn't
show what you changed, but everything that was changed by all other
people. This is why there are many changes and you don't recognize them.

If you want to check that you merged correctly, do this:
    "git diff b895c720^2 b895c720"
or equivalently (at least with bash) :
    git diff b895c720{^2,}
The "^2" part means "take second parent of given commit".

HTH,

-- 
Nicolas.