[PATCH] vcs_info git: Add a cherry-pick patch-format

[Daniel Shahaf <d.s@daniel.shahaf.name>]

---
Connect a 'git cherry-pick' that conflicted to patch-format.

Git doesn't make available as much information as we'd like, but I still
think this is useful.

diff --git a/Functions/VCS_Info/Backends/VCS_INFO_get_data_git b/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
index fcee47c..704c189 100644
--- a/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
+++ b/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
@@ -267,6 +267,28 @@ elif [[ -f "${gitdir}/MERGE_HEAD" ]]; then
     # Not touching git_patches_unapplied
 
     VCS_INFO_git_handle_patches
+elif [[ -f "${gitdir}/CHERRY_PICK_HEAD" ]]; then
+    # 'git cherry-pick' without -n, that conflicted.  (With -n, git doesn't
+    # record the CHERRY_PICK_HEAD information anywhere, as of git 2.6.2.)
+    #
+    # ### 'git cherry-pick foo bar baz' only records the "remaining" part of
+    # ### the queue in the .git dir: if 'bar' has a conflict, the .git dir 
+    # ### has a record of 'baz' being queued, but no record of 'foo' having been
+    # ### part of the queue as well.  Therefore, the %n/%c applied/unapplied
+    # ### expandos will be memoryless: the "applied" counter will always
+    # ### be "1".  The %u/%c tuple will assume the values [(1,2), (1,1), (1,0)],
+    # ### whereas the correct sequence would be [(1,2), (2,1), (3,0)].
+    local subject
+    IFS='' read -r subject < "${gitdir}/MERGE_MSG"
+    git_patches_applied=( "$(<${gitdir}/CHERRY_PICK_HEAD) ${subject}" )
+    if [[ -f "${gitdir}/sequencer/todo" ]]; then
+        # Get the next patches, and remove the one that's in CHERRY_PICK_HEAD.
+        git_patches_unapplied=( ${${(M)${(f)"$(<"${gitdir}/sequencer/todo")"}:#pick *}#pick } )
+        git_patches_unapplied[1]=()
+    else
+        git_patches_unapplied=()
+    fi
+    VCS_INFO_git_handle_patches
 else
     gitmisc=''
 fi