BUG: git can't handle certain kinds of renames in merges

git actually sucks at some merges 101 :P. I'm going to have to play with my test repository further because eventually I should be able to get git-write-tree failures making any kind of 'merge' impossible.

git://github.com/xenoterracide/git-test-case.git

clone that. checkout branch 1. then git merge master to see my end failure.

steps to create

add a file in a branch with a line (or more). create a new branch based on this branch and check it out. in the new branch mv the file into a directory with the same name as the file was. add -u and add the file so git sees the rename. checkout the original branch add some lines. checkout the new branch merge. the merge will go fine. remove a line from the new branches file. checkout master. add another line to that file. checkout new branch and attempt to merge.

you should now see the point that may test case is at.

On Mar 10, 2009, at 2:45 PM, Caleb Cushing wrote:

Yes, this is because automatic renaming detection fails with this kind of toy examples. Git can't infer the file was renamed because almost nothing is similar enough. Take a look at the attached script and run it with 'sh test.sh' and 'sh test.sh real_test', and look at the difference.

- Pieter

#!/usr/bin/bish
if test x$1 = x
then
	EXTRA_LINES=""
else
	EXTRA_LINES="line2\nline3\nline4\nline5"
fi
FILE1="a\n$EXTRA_LINES"
FILE2="a\n$EXTRA_LINES\nb"
FILE3="$EXTRA_LINES\nb"
FILE4="a\n$EXTRA_LINES\nb\nc"

echo -e $FILE2 rm -rf test_dir mkdir test_dir cd test_dir git init

echo -e $FILE1 > file git add file git commit -am "Initial"

git checkout -b branch git mv file a mkdir file git mv a file/file git commit -m "Move"

git checkout master echo -e $FILE2 > file git commit -am "Add a line"

git checkout branch git merge master

echo -e $FILE3 > file/file git commit -am "Remove line"

git checkout master echo -e $FILE4 > file git commit -am "Add another line"

git checkout branch git merge master

On Tue, Mar 10, 2009 at 12:02 PM, Pieter de Bie <pieter@frim.nl> wrote:

I've got a much bigger example(hundreds of lines, and dozens change at a time) which resolves in the same problem or worse with git-tree-write errors. I'm trying to figure out now how to work around this issue.