Fix roll-dep commit message on Windows and add suggestions

roll-dep would confidently print "Commit message:" but then on Windows
would only actually give the first line of the message to git. This is
because multi-line command-lines don't actually work on all shells. This
change passes the commit message using a temporary file so that the full
message is retained on all operating systems.

This change also teaches roll-dep to give suggestions when a specified
dependency is not quite correct. This is particularly helpful if a
leading or trailing directory name is used. For instance, this command
seems plausible:

  roll-dep third_party/openh264

But in fact it is wrong and a new user has to realize that a src prefix
is needed (in general) and in this specific case a src suffix is needed
as well. Prior to this change the error message would be:

    KeyError: 'Could not find any dependency called third_party/openh264.'

But after this message it will instead say:

    KeyError: 'Could not find any dependency called third_party/openh264. Did you mean src/third_party/openh264/src'

Past me wishes I'd done this years ago.

Change-Id: I6e0d6c703906b1c1ec947788fa259bae7b7520cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4120534
Reviewed-by: Joanna Wang <jojwang@chromium.org>
Commit-Queue: Bruce Dawson <brucedawson@chromium.org>

gclient_eval.py

@@ -42,7 +42,7 @@ class ConstantString(object):
     return self.value == other
 
   def __hash__(self):
-      return self.value.__hash__()
+    return self.value.__hash__()
 
 
 class _NodeDict(collections_abc.MutableMapping):
@@ -893,6 +893,15 @@ def GetCIPD(gclient_dict, dep_name, package_name):
 
 def GetRevision(gclient_dict, dep_name):
   if 'deps' not in gclient_dict or dep_name not in gclient_dict['deps']:
+    suggestions = []
+    if 'deps' in gclient_dict:
+      for key in gclient_dict['deps']:
+        if dep_name in key:
+          suggestions.append(key)
+    if suggestions:
+      raise KeyError(
+          "Could not find any dependency called %s. Did you mean %s" %
+          (dep_name, ' or '.join(suggestions)))
     raise KeyError(
         "Could not find any dependency called %s." % dep_name)
 

roll_dep.py

@@ -17,6 +17,7 @@ import os
 import re
 import subprocess2
 import sys
+import tempfile
 
 NEED_SHELL = sys.platform.startswith('win')
 GCLIENT_PATH = os.path.join(
@@ -187,7 +188,14 @@ def finalize(commit_msg, current_dir, rolls):
   print('\n'.join('    ' + i for i in commit_msg.splitlines()))
 
   check_call(['git', 'add', 'DEPS'], cwd=current_dir)
-  check_call(['git', 'commit', '--quiet', '-m', commit_msg], cwd=current_dir)
+  # We have to set delete=False and then let the object go out of scope so
+  # that the file can be opened by name on Windows.
+  with tempfile.NamedTemporaryFile('w+', newline='', delete=False) as f:
+    commit_filename = f.name
+    f.write(commit_msg)
+  check_call(['git', 'commit', '--quiet', '--file', commit_filename],
+             cwd=current_dir)
+  os.remove(commit_filename)
 
   # Pull the dependency to the right revision. This is surprising to users
   # otherwise.