From 0a7035170ac4927c90a614fa7287f7697b86be96 Mon Sep 17 00:00:00 2001
From: Daniel Shahaf <d.s@daniel.shahaf.name>
Date: Tue, 20 Oct 2015 03:07:04 +0000
Subject: [PATCH] versioning: Expose .revision-hash as $ZSH_HIGHLIGHT_REVISION.

Currently, this only works in installed trees and exported tarballs; the
parameter is left unset when running directly from a git worktree.
---
 zsh-syntax-highlighting.zsh | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/zsh-syntax-highlighting.zsh b/zsh-syntax-highlighting.zsh
index 54d52a1..bed6e64 100644
--- a/zsh-syntax-highlighting.zsh
+++ b/zsh-syntax-highlighting.zsh
@@ -32,6 +32,13 @@
 if [[ -o function_argzero ]]; then
   # $0 is reliable
   ZSH_HIGHLIGHT_VERSION=$(<"$0:h"/.version)
+  ZSH_HIGHLIGHT_REVISION=$(<"$0:h"/.revision-hash)
+  if [[ $ZSH_HIGHLIGHT_REVISION == \$Format:* ]]; then
+    # When running from a source tree without 'make install', $ZSH_HIGHLIGHT_REVISION
+    # would be set to '$Format:%H$' literally.  That's an invalid value, and obtaining
+    # the valid value (via `git rev-parse HEAD`, as Makefile does) might be costly, so:
+    unset ZSH_HIGHLIGHT_REVISION
+  fi
 else
   # $0 is unreliable, so the call to _zsh_highlight_load_highlighters will fail.
   # TODO: If 'zmodload zsh/parameter' is available, ${funcsourcetrace[1]%:*} might serve as a substitute?