[PATCH 2/2] vcs_info git: For the branch name, try to find a symbolic name before falling back to a raw commit hex.

[Daniel Shahaf <d.s@xxxxxxxxxxxxxxxxxx>]

Ask git-describe(1) and git-name-rev(1) to compute a gitrevisions(1)
name in terms of a branch or tag that contains (= is a descendant of,
is younger than) HEAD.

In this repository, the output changes from "9567bfe..." to
"master~1" or "remotes/origin/HEAD~1".
---
WDYT?

Cheers,

Daniel
(In HEAD, the branch name is already set to "heads/master" after `git checkout --detach master`.)

 Functions/VCS_Info/Backends/VCS_INFO_get_data_git | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Functions/VCS_Info/Backends/VCS_INFO_get_data_git b/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
index a44a62c79..c3e62db3a 100644
--- a/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
+++ b/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
@@ -106,6 +106,10 @@ VCS_INFO_git_getbranch () {
 
     elif gitbranch="$(${(z)gitsymref} 2> /dev/null)" ; then
     elif gitbranch="refs/tags/$(${vcs_comm[cmd]} describe --all --exact-match HEAD 2>/dev/null)" ; then
+    elif gitbranch="$(${vcs_comm[cmd]} describe --contains HEAD 2>/dev/null)" ; then
+    ## Commented out because we don't know of a case in which 'describe --contains' fails and 'name-rev --tags' succeeds.
+    #elif gitbranch="$(${vcs_comm[cmd]} name-rev --name-only --no-undefined --tags HEAD 2>/dev/null)" ; then
+    elif gitbranch="$(${vcs_comm[cmd]} name-rev --name-only --no-undefined --always HEAD 2>/dev/null)" ; then
     elif gitbranch="${${"$(< $gitdir/HEAD)"}[1,7]}..." ; then
     else
         # Can't happen