PATCH: (2/5) Add git's sha1 hash as revision information

[Frank Terbeck <ft@xxxxxxxxxxxxxxxxxxx>]

This does not mean, that the git backend supports a branchformat now.
Most people probably don't care about the sha1, so its retrieval is even
disabled by default. Still, I've seen people add such information to
their prompts, so vcs_info can do that now, too.

Example:
[snip]
autoload -Uz vcs_info; vcs_info

zstyle ':vcs_info:*'     max-exports    2
zstyle ':vcs_info:*'     formats        '(%s)-[%b]-'    '%i'
zstyle ':vcs_info:*'     actionformats  '(%s)-[%b|%a]-' '%i'
zstyle ':vcs_info:git:*' get-revision   true

function precmd() {
    psvar=()
    vcs_info
    [[ -n "${vcs_info_msg_0_}" ]] && psvar[1]="${vcs_info_msg_0_}"
    [[ -n "${vcs_info_msg_1_}" ]] && psvar[2]="${vcs_info_msg_1_[1,8]}"
}

PS1='%~%(1v. %1v.)%# '
RPS1='%(2v.[%2v].)'
[snap]
---
 Functions/VCS_Info/Backends/VCS_INFO_get_data_git |   17 +++++++++++++----
 1 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/Functions/VCS_Info/Backends/VCS_INFO_get_data_git b/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
index 745be34..faab2b8 100644
--- a/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
+++ b/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
@@ -3,7 +3,7 @@
 ## Distributed under the same BSD-ish license as zsh itself.
 
 setopt localoptions extendedglob NO_shwordsplit
-local gitdir gitbase gitbranch gitaction gitunstaged gitstaged
+local gitdir gitbase gitbranch gitaction gitunstaged gitstaged gitsha1
 
 VCS_INFO_git_getaction () {
     local gitaction='' gitdir=$1
@@ -77,7 +77,7 @@ VCS_INFO_git_getbranch () {
         gitbranch="$(${(z)gitsymref} 2> /dev/null)"
 
         if [[ $? -ne 0 ]] ; then
-            gitbranch="$(${vcs_comm[cmd]} describe --exact-match HEAD 2>/dev/null)"
+            gitbranch="refs/tags/$(${vcs_comm[cmd]} describe --exact-match HEAD 2>/dev/null)"
 
             if [[ $? -ne 0 ]] ; then
                 gitbranch="${${"$(< $gitdir/HEAD)"}[1,7]}..."
@@ -85,12 +85,21 @@ VCS_INFO_git_getbranch () {
         fi
     fi
 
-    printf '%s' "${gitbranch##refs/heads/}"
+    printf '%s' "${gitbranch}"
     return 0
 }
 
 gitdir=${vcs_comm[gitdir]}
 gitbranch="$(VCS_INFO_git_getbranch ${gitdir})"
+if zstyle -t ":vcs_info:${vcs}:${usercontext}:${rrn}" get-revision && \
+    [[ ${gitbranch} == refs/* ]] && \
+    [[ -r "${gitdir}/${gitbranch}" ]] ; then
+
+    gitsha1="${"$(< $gitdir/$gitbranch)"}"
+else
+    gitsha1=''
+fi
+gitbranch="${gitbranch##refs/[^/]##/}"
 
 if [[ -z ${gitdir} ]] || [[ -z ${gitbranch} ]] ; then
     return 1
@@ -108,5 +117,5 @@ VCS_INFO_adjust
 gitaction="$(VCS_INFO_git_getaction ${gitdir})"
 gitbase=${PWD%/${$( ${vcs_comm[cmd]} rev-parse --show-prefix )%/##}}
 rrn=${gitbase:t}
-VCS_INFO_formats "${gitaction}" "${gitbranch}" "${gitbase}" "${gitstaged}" "${gitunstaged}" '' ''
+VCS_INFO_formats "${gitaction}" "${gitbranch}" "${gitbase}" "${gitstaged}" "${gitunstaged}" "${gitsha1}" ''
 return 0
-- 
1.6.2.1.136.g8e24