Isolate the commands that raise OSError

Right now, running the git and hg commands could easily raise an
OSError. Let's only catch it in those cases and then use else to
install hooks when those are successful. Otherwise, pass on to the next
supported VCS

1 files changed, 6 insertions, 4 deletions

diff --git a/flake8/hooks.py b/flake8/hooks.py
index c25b9aa..14f844e 100644
--- a/flake8/hooks.py
+++ b/flake8/hooks.py
@@ -157,18 +157,20 @@ def _get_files(repo, **kwargs):
 def find_vcs():
     try:
         _, git_dir, _ = run('git rev-parse --git-dir')
+    except OSError:
+        pass
+    else:
         if git_dir and os.path.isdir(git_dir[0]):
             if not os.path.isdir(os.path.join(git_dir[0], 'hooks')):
                 os.mkdir(os.path.join(git_dir[0], 'hooks'))
             return os.path.join(git_dir[0], 'hooks', 'pre-commit')
-    except OSError:
-        pass
     try:
         _, hg_dir, _ = run('hg root')
-        if hg_dir and os.path.isdir(hg_dir[0]):
-            return os.path.join(hg_dir[0], '.hg', 'hgrc')
     except OSError:
         pass
+    else:
+        if hg_dir and os.path.isdir(hg_dir[0]):
+            return os.path.join(hg_dir[0], '.hg', 'hgrc')
     return ''