[PATCH 2 of 2] version: add extensions version info (issue4209)

[anatoly techtonik]

# HG changeset patch
# User anatoly techtonik <techtonik at gmail.com>
# Date 1402401369 -10800
#      Tue Jun 10 14:56:09 2014 +0300
# Branch stable
# Node ID 917c6c9356d47f3d3a97ca45967a1f91813c771a
# Parent  bd3150aeb5949c8ca2304bf52c6206730b73a8f9
version: add extensions version info (issue4209)

Query extensions for version info and format nicely into columns

diff -r bd3150aeb594 -r 917c6c9356d4 mercurial/commands.py
--- a/mercurial/commands.py	Tue Jun 10 13:44:37 2014 +0300
+++ b/mercurial/commands.py	Tue Jun 10 14:56:09 2014 +0300
@@ -14,6 +14,7 @@
 import patch, help, encoding, templatekw, discovery
 import archival, changegroup, cmdutil, hbisect
 import sshserver, hgweb, commandserver
+from extensions import extensions
 from hgweb import server as hgweb_server
 import merge as mergemod
 import minirst, revset, fileset
@@ -5908,6 +5909,29 @@
     """
     return hg.verify(repo)
 
+
+def moduleversion(module):
+    """gets version information from the module
+
+    This code was inspired by Django Debug Toolbar's VersionDebugPanel.
+    """
+    extension = module
+    if hasattr(extension, 'get_version'):
+        get_version = extension.get_version
+        if callable(get_version):
+            version = get_version()
+        else:
+            version = get_version
+    elif hasattr(extension, 'VERSION'):
+        version = extension.VERSION
+    elif hasattr(extension, '__version__'):
+        version = extension.__version__
+    else:
+        version = ''
+    if isinstance(version, (list, tuple)):
+        version = '.'.join(str(o) for o in version)
+    return version
+
 @command('version', [])
 def version_(ui):
     """output version and copyright information"""
@@ -5930,8 +5954,14 @@
     # by Markus Zapke-Gruendemann <info at keimlink.de>
     ui.note(_("\nEnabled extensions:\n\n"))
     if ui.verbose:
-        for name, module in ui.configitems('extensions'):
-            ui.write("  %s\n" % name)
+        names = []
+        vers = [] 
+        for name, module in extensions():
+            names.append(name)
+            vers.append(moduleversion(module))
+        maxnamelen = max(len(n) for n in names)
+        for i,n in enumerate(names):
+            ui.write("  %s  %s\n" % (n.ljust(maxnamelen), vers[i]))
 
 
 norepo = ("clone init version help debugcommands debugcomplete"