git pull fails with merge conflicts. How can this possibly happen?

[Alan Mackenzie]

Hello, Emacs.

I've now advanced from my last puzzlement.  It turns out that "git
clone" doesn't properly initialise the new repository.  I had to do this
manually with "git checkout emacs-24".  I now get a bit further with
"git pull" from my other repository.

This "git pull" leaves a mass of merge conflicts.  How can this be?  I
have not edited a single file in any git repository as of yet.  Here is
a screen shot from this "git pull" together with a preceeding "git
branch -a":

  address@hidden ~/emacs/emacs.git/emacs-24 $ git branch -a
  * emacs-24
    master
    remotes/origin/HEAD -> origin/master
    remotes/origin/emacs-24
    remotes/origin/master
  address@hidden ~/emacs/emacs.git/emacs-24 $ git pull
  remote: Counting objects: 32, done.
  remote: Compressing objects: 100% (16/16), done.
  remote: Total 32 (delta 26), reused 22 (delta 16)
  Unpacking objects: 100% (32/32), done.
  From /home/acm/emacs/emacs.git/master/.
   + 911ad4a...6688117 emacs-24   -> origin/emacs-24  (forced update)
  Auto-merging src/nsfns.m
  Auto-merging src/ChangeLog
  CONFLICT (content): Merge conflict in src/ChangeLog
  Auto-merging lisp/gnus/ChangeLog
  CONFLICT (content): Merge conflict in lisp/gnus/ChangeLog
  Auto-merging etc/ChangeLog
  CONFLICT (content): Merge conflict in etc/ChangeLog
  Auto-merging etc/CONTRIBUTE
  Auto-merging admin/ChangeLog
  CONFLICT (content): Merge conflict in admin/ChangeLog
  Auto-merging Makefile.in
  CONFLICT (content): Merge conflict in Makefile.in
  Auto-merging ChangeLog
  CONFLICT (content): Merge conflict in ChangeLog
  Auto-merging .gitignore
  CONFLICT (content): Merge conflict in .gitignore
  Automatic merge failed; fix conflicts and then commit the result.

What does git pull actually do?  The git pull man page says:

  "Incorporates changes from a remote repository into the current
   branch. In its default mode, git pull is shorthand for git fetch
   followed by git merge FETCH_HEAD."

Does this mean that git has tried to merge changes on the master branch
into my emacs-24 branch working directory?  Surely git can't be that
stupid.  Please?

-- 
Alan Mackenzie (Nuremberg, Germany).