Merge lp:~mvo/snappy/snappy-panic-less into lp:~snappy-dev/snappy/snappy-moved-to-github

[Michael Vogt]

Tiny branch that fixes a panic when doing:
"""
priv := New(lockfile)
priv.Lock()
priv.Unlock()
priv.Lock()
"""

Kudos to John Lenton for discovering this isssue.

[John Lenton (chipaca)]

Hah.

I didn't do this myself because I didn't understand why it was being nil'ed, so left it alone.

That it can be removed entirely is good news :)

review: Approve

[Michael Vogt (mvo)]

On Thu, Oct 22, 2015 at 09:38:50AM -0000, John Lenton wrote:
> Review: Approve
>
> Hah.
>
> I didn't do this myself because I didn't understand why it was being nil'ed, so left it alone.
>
> That it can be removed entirely is good news :)

I don't know either (I didn't write the code), but looking at the code
I don't think its required (famous last words) so lets fix it and see
what breaks.

Thanks,
 Michael

Unmerged revisions

794. By Michael Vogt on 2015-10-22

do not panic if a priv.Mutex is taken/released/taken again

=== modified file 'priv/priv.go'
--- priv/priv.go	2015-06-17 18:34:42 +0000
+++ priv/priv.go	2015-10-22 08:36:17 +0000
@@ -100,9 +100,6 @@
 		return err
 	}
 
-	// invalidate
-	m.lock = nil
-
 	return nil
 }
 
 
=== modified file 'priv/priv_test.go'
--- priv/priv_test.go	2015-06-15 07:32:58 +0000
+++ priv/priv_test.go	2015-10-22 08:36:17 +0000
@@ -73,7 +73,6 @@
 
 	err = privMutex.Unlock()
 	c.Assert(err, IsNil)
-	c.Assert(privMutex.lock, IsNil)
 	c.Assert(helpers.FileExists(lockfile), Equals, false)
 }
 
@@ -141,3 +140,12 @@
 	// and we did not call it too often
 	c.Assert(callCount, Equals, 1)
 }
+
+func (ts *PrivTestSuite) TestPrivLockLock(c *C) {
+	lockfile := filepath.Join(ts.tempdir, "lock")
+	priv := New(lockfile)
+	for i := 0; i < 3; i++ {
+		priv.Lock()
+		priv.Unlock()
+	}
+}