[gimp] app: define GIMP_GIT_LAST_COMMIT_{TIMESTAMP,YEAR} macros

[Nils Philippsen <nphilipp src gnome org>]

commit 37d98767423151430e42e88e33c7e7c7156c8b1d
Author: Nils Philippsen <nils redhat com>
Date:   Fri Sep 17 11:52:45 2010 +0200

    app: define GIMP_GIT_LAST_COMMIT_{TIMESTAMP,YEAR} macros

 app/Makefile.am |   17 ++++++++++++++---
 1 files changed, 14 insertions(+), 3 deletions(-)
---
diff --git a/app/Makefile.am b/app/Makefile.am
index 1f7e897..c68de37 100644
--- a/app/Makefile.am
+++ b/app/Makefile.am
@@ -268,10 +268,21 @@ dist-hook: dist-check-gimp-console dist-dump-gimprc
 # in which case the git-version.h we ship is correct.
 git-version.h: update-git-version-header
 	@if test -d "$(top_srcdir)/.git"; then \
-	  echo "#define GIMP_GIT_VERSION \"`git describe`\"" > "$  tmp"; \
+	  git_version="`git describe`"; \
+	  git_last_commit_timestamp="`git log -n1 --reverse --pretty=%ct`"; \
+	  git_last_commit_year="`date --utc -d \"1970-01-01 + $$git_last_commit_timestamp seconds\" '+%Y'`"; \
 	elif test ! -f "$@"; then \
-	  echo "#define GIMP_GIT_VERSION \"Unknown, shouldn't happen\"" > "$  tmp"; \
-	fi
+	  git_version="Unknown, shouldn't happen"; \
+	  git_last_commit_timestamp=-1; \
+	  git_last_commit_year="`date --utc '+%Y'`"; \
+	fi; \
+	echo "#ifndef __GIT_VERSION_H__" > "$  tmp"; \
+	echo "#define __GIT_VERSION_H__" >> "$  tmp"; \
+	echo "#include <time.h>" >> "$  tmp"; \
+	echo "#define GIMP_GIT_VERSION \"$$git_version\"" >> "$  tmp"; \
+	echo "#define GIMP_GIT_LAST_COMMIT_TIMESTAMP ((time_t)$$git_last_commit_timestamp)" >> "$  tmp"; \
+	echo "#define GIMP_GIT_LAST_COMMIT_YEAR \"$$git_last_commit_year\"" >> "$  tmp"; \
+	echo "#endif /* __GIT_VERSION_H__ */" >> "$  tmp"
 	@if ( test -f "$  tmp" && test -f "$@" && cmp "$  tmp" "$@" > /dev/null ); then \
 	  rm -f "$  tmp"; \
 	elif test -f "$  tmp"; then \