Make whitespace commit hook better at finding the hg executable

Fixes compatibility issues with MacHG and probably GUIs. (Note that the released version of MacHG actually doesn't work at the moment, but new ones should soon -- cf. http://bitbucket.org/jfh/machg/issue/141/p2d2-environment-variables-not-set)

Make whitespace commit hook better at finding the hg executable
96c0e229 · Josh Bleecher Snyder · 221b58bd · 96c0e229
--- a/theano/misc/hooks/check_whitespace.py
+++ b/theano/misc/hooks/check_whitespace.py
@@ -81,8 +81,11 @@ class MercurialRuntimeError(Exception):
    pass

 def run_mercurial_command(hg_command):
+    hg_executable = os.environ.get("HG", None) or "hg"
+    hg_command_tuple = hg_command.split()
+    hg_command_tuple.insert(0, hg_executable)
    try:
-        hg_subprocess = Popen(hg_command.split(), stdout=PIPE, stderr=PIPE)
+        hg_subprocess = Popen(hg_command_tuple, stdout=PIPE, stderr=PIPE)
    except OSError:
        print >> sys.stderr, "Can't find the hg executable!"
        sys.exit(1)
@@ -99,22 +102,22 @@ def parse_stdout_filelist(hg_out_filelist):
    return files

 def changed_files():
-    hg_out = run_mercurial_command("hg tip --template '{file_mods}'")
+    hg_out = run_mercurial_command("tip --template '{file_mods}'")
    return parse_stdout_filelist(hg_out)

 def added_files():
-    hg_out = run_mercurial_command("hg tip --template '{file_adds}'")
+    hg_out = run_mercurial_command("tip --template '{file_adds}'")
    return parse_stdout_filelist(hg_out)

 def is_python_file(filename):
    return filename.endswith(".py")

 def get_file_contents(filename, revision="tip"):
-    hg_out = run_mercurial_command("hg cat -r %s %s" % (revision, filename))
+    hg_out = run_mercurial_command("cat -r %s %s" % (revision, filename))
    return hg_out

 def save_commit_message(filename):
-    commit_message = run_mercurial_command("hg tip --template '{desc}'")
+    commit_message = run_mercurial_command("tip --template '{desc}'")
    save_file = open(filename, "w")
    save_file.write(commit_message)
    save_file.close()