Add InputApi.ReadFile() and presubmit_canned_checks.CheckChangeHasNoCR().

presubmit_support.py

Index: presubmit_support.py
diff --git a/presubmit_support.py b/presubmit_support.py
index 86398cb8f2f07166af24d6544c373bfa67968dae..f83f4bd090ac1a5b391a9402b2c910583ae6bbfa 100755
--- a/presubmit_support.py
+++ b/presubmit_support.py
@@ -6,7 +6,7 @@
 """Enables directory-specific presubmit checks to run at upload and/or commit.
 """
 
-__version__ = '1.3'
+__version__ = '1.3.1'
 
 # TODO(joi) Add caching where appropriate/needed. The API is designed to allow
 # caching (between all different invocations of presubmit scripts for a given
@@ -271,6 +271,16 @@ class InputApi(object):
         filter(lambda x: x.IsTextFile(),
                self.AffectedFiles(include_deletes=False)))
 
+  def ReadFile(self, file, mode='r'):
+    """Reads an arbitrary file.
+    
+    Deny reading anything outside the repository."""

[Jói Sigurðsson, 2009/06/08 10:52:50]

For consistency with the rest of the code, please do multi-line docstrings with
the trailing quote on a separate line:

"""foo
blat
gat.
"""

Single-line docstrings should still be on a single line,

"""Foo blat gat."""

+    if isinstance(file, AffectedFile):
+      file = file.AbsoluteLocalPath()
+    if not file.startswith(self.change.RepositoryRoot()):
+      raise IOError('Access outside the repository root is denied.')
+    return gcl.ReadFile(file, mode)
+
   @staticmethod
   def _RightHandSideLinesImpl(affected_files):
     """Implements RightHandSideLines for InputApi and GclChange."""