Add git commit to the reported version with -v

When git is available, records the git commit in the dillo binary, so
dillo -v reports the version and the commit. Otherwise only the release
version is reported (as we do now).

The commit is *always* recomputed when "make" is called. This allows
switching branches, doing a dirty rebuild and still get the correct
commit with "dillo -v".

Using AC_INIT() doesn't update the commit when the source is already
configured.

Fixes: https://github.com/dillo-browser/dillo/issues/288

2 files changed, 24 insertions, 1 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 34c05e30..c0205f7d 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -138,5 +138,21 @@ dillo_SOURCES = \
 	xembed.cc \
 	xembed.hh
 
+# https://www.gnu.org/software/automake/manual/html_node/Built-Sources-Example.html
+nodist_dillo_SOURCES = commit.h
+dillo.$(OBJEXT): commit.h
+CLEANFILES = commit.h
+
+if GIT_AVAILABLE
+# Always rebuild
+.PHONY: commit.h
+commit.h:
+	printf '#define GIT_COMMIT "%s"\n' `git --work-tree="$(top_srcdir)" describe --dirty` > commit.h
+else
+# No need to rebuild
+commit.h:
+	echo "" > commit.h
+endif # GIT_AVAILABLE
+
 dist_sysconf_DATA = domainrc keysrc hsts_preload
 EXTRA_DIST = chg srch
diff --git a/src/version.cc b/src/version.cc
index f118c202..44b894e5 100644
--- a/src/version.cc
+++ b/src/version.cc
@@ -18,6 +18,7 @@
  */
 
 #include "config.h"
+#include "commit.h"
 
 #include "djpeg.h"
 #include "dpng.h"
@@ -114,7 +115,13 @@ static void print_features()
 
 void a_Version_print_info(void)
 {
-   printf("Dillo version " VERSION "\n");
+   const char *version = "v" VERSION;
+
+#ifdef GIT_COMMIT
+   version = GIT_COMMIT;
+#endif
+
+   printf("Dillo %s\n", version);
    print_libs();
    print_features();
 }