If the destination directory doesn't contain the desired repo, delete it

tests/gclient_smoketest.py

Index: tests/gclient_smoketest.py
diff --git a/tests/gclient_smoketest.py b/tests/gclient_smoketest.py
index c05bbf339de4f23118bb331f71976d199f1db9a0..833c9103da58c2416379fe03fb565eadc1127992 100755
--- a/tests/gclient_smoketest.py
+++ b/tests/gclient_smoketest.py
@@ -1343,6 +1343,76 @@ class GClientSmokeBoth(GClientSmokeBase):
 
     self.assertEquals(sorted(entries), sorted(expected))
 
+  def testDeleteConflictingCheckout(self):
+    if not self.enabled:
+      return
+
+    # Create an initial svn checkout.
+    self.gclient(['config', '--spec',
+        'solutions=['
+        '{"name": "src",'
+        ' "url": "' + self.svn_base + 'trunk/src"},'
+        ']'
+    ])
+    results = self.gclient(['sync', '--deps', 'mac'])
+    self.assertEqual(results[2], 0, 'Sync failed!')
+
+    # Verify that we have the expected svn checkout.
+    results = self.gclient(['revinfo', '--deps', 'mac'])
+    actual = results[0].splitlines()
+    expected = [
+      'src: %strunk/src' % self.svn_base,
+      'src/file/other: File("%strunk/other/DEPS")' % self.svn_base,
+      'src/other: %strunk/other' % self.svn_base,
+      'src/third_party/foo: %strunk/third_party/foo@1' % self.svn_base,
+    ]
+    self.assertEquals(actual, expected)
+
+    # Change the desired checkout to git.
+    self.gclient(['config', '--spec',
+        'solutions=['
+        '{"name": "src",'
+        ' "url": "' + self.git_base + 'repo_1"},'
+        ']'
+    ])
+
+    # Verify that the sync succeeds with --force.
+    results = self.gclient(['sync', '--deps', 'mac', '--force'])
+    self.assertEqual(results[2], 0, 'Sync failed!')
+
+    # Verify that we got the desired git checkout.
+    results = self.gclient(['revinfo', '--deps', 'mac'])
+    actual = results[0].splitlines()
+    expected = [
+      'src: %srepo_1' % self.git_base,
+      'src/repo2: %srepo_2@%s' % (self.git_base, self.githash('repo_2', 1)[:7]),
+      'src/repo2/repo_renamed: %srepo_3' % self.git_base,
+    ]
+    self.assertEquals(actual, expected)
+
+    # Change the desired checkout back to svn.
+    self.gclient(['config', '--spec',
+        'solutions=['
+        '{"name": "src",'
+        ' "url": "' + self.svn_base + 'trunk/src"},'
+        ']'
+    ])
+
+    # Verify that the sync succeeds.
+    results = self.gclient(['sync', '--deps', 'mac', '--force'])
+    self.assertEqual(results[2], 0, 'Sync failed!')
+
+    # Verify that we have the expected svn checkout.
+    results = self.gclient(['revinfo', '--deps', 'mac'])
+    actual = results[0].splitlines()
+    expected = [
+      'src: %strunk/src' % self.svn_base,
+      'src/file/other: File("%strunk/other/DEPS")' % self.svn_base,
+      'src/other: %strunk/other' % self.svn_base,
+      'src/third_party/foo: %strunk/third_party/foo@1' % self.svn_base,
+    ]
+    self.assertEquals(actual, expected)
+
 
 class GClientSmokeFromCheckout(GClientSmokeBase):
   # WebKit abuses this. It has a .gclient and a DEPS from a checkout.