Show the git branch and last commit ID in the desktop app About box.

_freeze.py

@@ -4,10 +4,12 @@
 import sys
 import os
 import shutil
+import subprocess
 import tempfile
 import time
 import datetime
 import json
+import re
 import getopt
 
 from PyInstaller.__main__ import run as run_pyinstaller
@@ -24,6 +26,32 @@ DEFAULT_TARGET_NAME = "vasl-templates"
 
 # ---------------------------------------------------------------------
 
+def get_git_info():
+    """Get the git branch/commit we're building from."""
+
+    # get the latest commit ID
+    proc = subprocess.run(
+        [ "git", "log" ],
+        stdout=subprocess.PIPE, stderr=subprocess.PIPE, encoding="utf-8"
+    )
+    buf = proc.stdout.split( "\n" )[0]
+    mo = re.search( r"^commit ([a-z0-9]+)$", buf )
+    last_commit_id = mo.group(1)
+
+    # get the current git branch
+    proc = subprocess.run(
+        [ "git", "branch" ],
+        stdout=subprocess.PIPE, stderr=subprocess.PIPE, encoding="utf-8"
+    )
+    lines = [ s for s in proc.stdout.split("\n") if s.startswith("* ") ]
+    if len(lines) != 1:
+        raise RuntimeError( "Can't parse git branch status." )
+    branch_name = lines[0][2:]
+
+    return { "last_commit_id": last_commit_id, "branch_name": branch_name }
+
+# ---------------------------------------------------------------------
+
 # parse the command-line options
 output_fname = None
 work_dir = None
@@ -131,6 +159,7 @@ for f in fnames:
 build_info = {
     "timestamp": int( time.time() ),
 }
+build_info.update( get_git_info() )
 dname = os.path.join( dist_dir, "config" )
 with open( os.path.join(dname,"build-info.json"), "w" ) as fp:
     json.dump( build_info, fp )

vasl_templates/about.py

@@ -3,6 +3,7 @@
 import os
 import json
 import time
+import io
 
 from PyQt5 import uic
 from PyQt5.QtWidgets import QDialog
@@ -38,10 +39,18 @@ class AboutDialog( QDialog ):
         self.app_name.setText( "{} ({})".format( APP_NAME, APP_VERSION ) )
         self.license.setText( "Licensed under the GNU Affero General Public License (v3)." )
         if build_info:
+            buf = io.StringIO()
             timestamp = build_info[ "timestamp" ]
-            self.build_info.setText( "Built {}.".format(
+            buf.write( "Built {}".format(
                 time.strftime( "%d %B %Y %H:%S", time.localtime( timestamp ) ) # nb: "-d" doesn't work on Windows :-/
             ) )
+            if "branch_name" in build_info or "last_commit_id" in build_info:
+                buf.write( " <small><em>({}".format( build_info["branch_name"] ) )
+                if "last_commit_id" in build_info:
+                    buf.write( ":{}".format( build_info["last_commit_id"][:8] ) )
+                buf.write( ")</em></small>" )
+            buf.write( "." )
+            self.build_info.setText( buf.getvalue() )
         else:
             self.build_info.setText( "" )
         self.home_url.setText(