Fix use_relative_path on Windows

DEPS entries all have slashes as their path separators.

If use_relative_path is set to true, .gclient_entries will actually
contain backslashes instead slashes. This is problematic when DEPS
file transitions from using use_relative_path = False to True.

In such case, gclient thinks there are two distinct repositories
and it will delete one with slashes. As this operation is the last
step of gclient sync, it results in affected repositories being
wrongfully removed.

This change forces all deps entries to have slashes regardless of
operating system.

R=gavinmak@google.com

Bug: 1422665
Change-Id: Idb73510d911a260bccf63d24a8d3452998b147f7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4348792
Commit-Queue: Josip Sokcevic <sokcevic@chromium.org>
Commit-Queue: Gavin Mak <gavinmak@google.com>
Reviewed-by: Gavin Mak <gavinmak@google.com>
Auto-Submit: Josip Sokcevic <sokcevic@chromium.org>

gclient.py

@@ -680,7 +680,11 @@ class Dependency(gclient_utils.WorkItem, DependencySettings):
     for d, url in processed_deps.items():
       # normpath is required to allow DEPS to use .. in their
       # dependency local path.
-      rel_deps[os.path.normpath(os.path.join(rel_prefix, d))] = url
+      # We are following the same pattern when use_relative_paths = False,
+      # which uses slashes.
+      rel_deps[os.path.normpath(os.path.join(rel_prefix,
+                                             d)).replace(os.path.sep,
+                                                         '/')] = url
     logging.warning('Updating deps by prepending %s.', rel_prefix)
     return rel_deps
 
@@ -842,8 +846,8 @@ class Dependency(gclient_utils.WorkItem, DependencySettings):
         logging.warning('Updating recursedeps by prepending %s.', rel_prefix)
         rel_deps = {}
         for depname, options in self.recursedeps.items():
-          rel_deps[
-              os.path.normpath(os.path.join(rel_prefix, depname))] = options
+          rel_deps[os.path.normpath(os.path.join(rel_prefix, depname)).replace(
+              os.path.sep, '/')] = options
         self.recursedeps = rel_deps
     # To get gn_args from another DEPS, that DEPS must be recursed into.
     if self._gn_args_from:

tests/gclient_test.py

@@ -440,11 +440,10 @@ class GclientTest(trial_dir.TestCase):
     write(os.path.join('foo', 'baz', 'fake.txt'),
           "bogus content")
 
-    self.assertEqual([(h.action, h.effective_cwd) for h in self._get_hooks()],
-        [
-            (('tata', 'titi'), self.root_dir),
-            (('fire', 'lazors'), os.path.join(self.root_dir, "foo", "baz"))
-        ])
+    self.assertEqual(
+        [(h.action, h.effective_cwd) for h in self._get_hooks()],
+        [(('tata', 'titi'), self.root_dir),
+         (('fire', 'lazors'), os.path.join(self.root_dir, 'foo/baz'))])
 
   def testTargetOS(self):
     """Verifies that specifying a target_os pulls in all relevant dependencies.
@@ -847,13 +846,11 @@ class GclientTest(trial_dir.TestCase):
     options, _ = gclient.OptionParser().parse_args([])
     obj = gclient.GClient.LoadCurrentConfig(options)
     obj.RunOnDeps('None', [])
-    self.assertEqual(
-        [
-          ('foo', 'svn://example.com/foo'),
-          (os.path.join('foo', 'bar'), 'svn://example.com/bar'),
-          (os.path.join('foo', 'baz'), 'svn://example.com/baz'),
-        ],
-        self._get_processed())
+    self.assertEqual([
+        ('foo', 'svn://example.com/foo'),
+        ('foo/bar', 'svn://example.com/bar'),
+        ('foo/baz', 'svn://example.com/baz'),
+    ], self._get_processed())
 
   def testRecursedepsCustomdepsOverride(self):
     """Verifies gclient overrides deps within recursedeps using custom deps"""
@@ -883,15 +880,12 @@ class GclientTest(trial_dir.TestCase):
     options, _ = gclient.OptionParser().parse_args([])
     obj = gclient.GClient.LoadCurrentConfig(options)
     obj.RunOnDeps('None', [])
-    six.assertCountEqual(
-        self,
-        [
-          ('foo', 'svn://example.com/foo'),
-          (os.path.join('foo', 'bar'), 'svn://example.com/override'),
-          (os.path.join('foo', 'foo', 'bar'), 'svn://example.com/override'),
-          (os.path.join('foo', 'baz'), 'svn://example.com/baz'),
-        ],
-        self._get_processed())
+    six.assertCountEqual(self, [
+        ('foo', 'svn://example.com/foo'),
+        ('foo/bar', 'svn://example.com/override'),
+        ('foo/foo/bar', 'svn://example.com/override'),
+        ('foo/baz', 'svn://example.com/baz'),
+    ], self._get_processed())
 
   def testRelativeRecursion(self):
     """Verifies that nested use_relative_paths is always respected."""
@@ -922,13 +916,11 @@ class GclientTest(trial_dir.TestCase):
     options, _ = gclient.OptionParser().parse_args([])
     obj = gclient.GClient.LoadCurrentConfig(options)
     obj.RunOnDeps('None', [])
-    self.assertEqual(
-        [
-          ('foo', 'svn://example.com/foo'),
-          (os.path.join('foo', 'bar'), 'svn://example.com/bar'),
-          (os.path.join('foo', 'bar', 'baz'), 'svn://example.com/baz'),
-        ],
-        self._get_processed())
+    self.assertEqual([
+        ('foo', 'svn://example.com/foo'),
+        ('foo/bar', 'svn://example.com/bar'),
+        ('foo/bar/baz', 'svn://example.com/baz'),
+    ], self._get_processed())
 
   def testRelativeRecursionInNestedDir(self):
     """Verifies a gotcha of relative recursion where the parent uses relative
@@ -961,13 +953,11 @@ class GclientTest(trial_dir.TestCase):
     options, _ = gclient.OptionParser().parse_args([])
     obj = gclient.GClient.LoadCurrentConfig(options)
     obj.RunOnDeps('None', [])
-    self.assertEqual(
-        [
-          ('foo', 'svn://example.com/foo'),
-          (os.path.join('foo', 'third_party', 'bar'), 'svn://example.com/bar'),
-          (os.path.join('foo', 'third_party', 'baz'), 'svn://example.com/baz'),
-        ],
-        self._get_processed())
+    self.assertEqual([
+        ('foo', 'svn://example.com/foo'),
+        ('foo/third_party/bar', 'svn://example.com/bar'),
+        ('foo/third_party/baz', 'svn://example.com/baz'),
+    ], self._get_processed())
 
   def testRecursedepsAltfile(self):
     """Verifies gclient respects the |recursedeps| var syntax with overridden