GIT-MERGE-INDEX(1)                                           Git Manual                                          GIT-MERGE-INDEX(1)

       git-merge-index - Run a merge for files needing merging

       git merge-index [-o] [-q] <merge-program> (-a | ( [--] <file>...) )

       This looks up the <file>(s) in the index and, if there are any merge entries, passes the SHA-1 hash for those files as
       arguments 1, 2, 3 (empty argument if no file), and <file> as argument 4. File modes for the three files are passed as
       arguments 5, 6 and 7.

           Do not interpret any more arguments as options.

           Run merge against all files in the index that need merging.

           Instead of stopping at the first failed merge, do all of them in one shot - continue with merging even when previous
           merges returned errors, and only return the error code after all the merges.

           Do not complain about a failed merge program (a merge program failure usually indicates conflicts during the merge).
           This is for porcelains which might want to emit custom messages.

       If git merge-index is called with multiple <file>s (or -a) then it processes them in turn only stopping if merge returns a
       non-zero exit code.

       Typically this is run with a script calling Git’s imitation of the merge command from the RCS package.

       A sample script called git merge-one-file is included in the distribution.

       ALERT ALERT ALERT! The Git "merge object order" is different from the RCS merge program merge object order. In the above
       ordering, the original is first. But the argument order to the 3-way merge program merge is to have the original in the
       middle. Don’t ask me why.


           torvalds@ppc970:~/merge-test> git merge-index cat MM
           This is MM from the original tree.              # original
           This is modified MM in the branch A.            # merge1
           This is modified MM in the branch B.            # merge2
           This is modified MM in the branch B.            # current contents


           torvalds@ppc970:~/merge-test> git merge-index cat AA MM
           cat: : No such file or directory
           This is added AA in the branch A.
           This is added AA in the branch B.
           This is added AA in the branch B.
           fatal: merge program failed

       where the latter example shows how git merge-index will stop trying to merge once anything has returned an error (i.e., cat
       returned an error for the AA file, because it didn’t exist in the original, and thus git merge-index didn’t even try to
       merge the MM thing).

       Part of the git(1) suite

Git 2.39.2                                                   04/24/2023                                          GIT-MERGE-INDEX(1)