--- a/hgext/convert/git.py	Sat Aug 25 12:25:53 2007 -0700
+++ b/hgext/convert/git.py	Sun Aug 26 16:49:26 2007 +0200
@@ -5,8 +5,23 @@
 from common import NoRepo, commit, converter_source
 
 class convert_git(converter_source):
-    def gitcmd(self, s):
-        return os.popen('GIT_DIR=%s %s' % (self.path, s))
+    # Windows does not support GIT_DIR= construct while other systems
+    # cannot remove environment variable. Just assume none have
+    # both issues.
+    if hasattr(os, 'unsetenv'):
+        def gitcmd(self, s):
+            prevgitdir = os.environ.get('GIT_DIR')
+            os.environ['GIT_DIR'] = self.path
+            try:
+                return os.popen(s)
+            finally:
+                if prevgitdir is None:
+                    del os.environ['GIT_DIR']
+                else:
+                    os.environ['GIT_DIR'] = prevgitdir
+    else:
+        def gitcmd(self, s):
+            return os.popen('GIT_DIR=%s %s' % (self.path, s))
 
     def __init__(self, ui, path, rev=None):
         super(convert_git, self).__init__(ui, path, rev=rev)

--- a/tests/hghave	Sat Aug 25 12:25:53 2007 -0700
+++ b/tests/hghave	Sun Aug 26 16:49:26 2007 +0200
@@ -51,9 +51,16 @@
     except ImportError:
         return False
 
+def has_git():
+    fh = os.popen('git --version 2>&1')
+    s = fh.read()
+    ret = fh.close()
+    return ret is None and s.startswith('git version')
+
 checks = {
     "eol-in-paths": (has_eol_in_paths, "end-of-lines in paths"),
     "execbit": (has_executablebit, "executable bit"),
+    "git": (has_git, "git command line client"),
     "fifo": (has_fifo, "named pipes"),
     "hotshot": (has_hotshot, "python hotshot module"),
     "lsprof": (has_lsprof, "python lsprof module"),

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-convert-git	Sun Aug 26 16:49:26 2007 +0200
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+"$TESTDIR/hghave" git || exit 80
+
+echo "[extensions]" >> $HGRCPATH
+echo "convert=" >> $HGRCPATH
+
+mkdir git-repo
+cd git-repo
+git init
+echo a > a
+git add a
+git commit -m t1 > /dev/null || echo "git commit error"
+echo b >> a
+git commit -a -m t2 > /dev/null || echo "git commit error"
+cd ..
+
+hg convert git-repo
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-convert-git.out	Sun Aug 26 16:49:26 2007 +0200
@@ -0,0 +1,8 @@
+Initialized empty Git repository in .git/
+assuming destination git-repo-hg
+initializing destination git-repo-hg repository
+scanning source...
+sorting...
+converting...
+1 t1
+0 t2