Fix get_files_affected_by_patch to work with spaces in file names.

Bug: 1288604
Change-Id: Ie116316062e50138668299538a5e0759a1dd3fa9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3459466
Auto-Submit: Garrett Beaty <gbeaty@google.com>
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

recipes/recipe_modules/tryserver/api.py

@@ -253,7 +253,7 @@ class TryserverApi(recipe_api.RecipeApi):
             self.m.raw_io.test_api.stream_output('foo.cc'),
           **kwargs)
     paths = [self.m.path.join(patch_root, p.decode('utf-8')) for p in
-             step_result.stdout.split()]
+             step_result.stdout.splitlines()]
     paths.sort()
     if self.m.platform.is_win:
       # Looks like "analyze" wants POSIX slashes even on Windows (since git

recipes/recipe_modules/tryserver/tests/get_files_affected_by_patch.py

@@ -90,3 +90,14 @@ def GenTests(api):
       api.post_check(post_process.StatusSuccess),
       api.post_process(post_process.DropExpectation),
   )
+
+  yield api.test(
+      'file-with-spaces',
+      api.tryserver.get_files_affected_by_patch(['file with spaces.txt']),
+      api.properties(
+          patch_root='',
+          expected_files=['file with spaces.txt'],
+      ),
+      api.post_check(post_process.StatusSuccess),
+      api.post_process(post_process.DropExpectation),
+  )
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