Revision 1877712

entries-dump: Escape string-typed attribute values when serializing
them as Python string literals.

Before this commit, a filesystem node named "foo\bar" (a single,
7-character path component) would cause "e.name = 'foo\bar'" to be
emitted.  In genral, the unescaped backslash would manifest as a test
failure or a SyntaxError, depending on the following characters.

This was triggered by update_tests.py 76 windows_update_backslash under
Python 3 on Windows.

There can be some other characters that should be escaped.  For example,
user names can contain "'" (a single quote character) and/or """ (a
double quote character), which would potentially cause a SyntaxError
even if we choose either of them to quote string literals.  To avoid
overlooking such potentially unsafe characters, I decided to use hex
value escape for all characters.  

Furthermore, to ensure that values are decoded to Unicode as UTF-8 byte
sequences when we use hex value escape under Python 3, we print them as
bytes values and then encode them.

* subversion/tests/cmdline/entries-dump.c
  (print_prefix): New function.
  (str_value):
  - Add argument to specify pool.
  - Print human readable value of "value" as is in comment, then set it
    as str value by using hex escaped bytes literal.
  (entries_dump): Add pool argument to str_value() calls.
  (main):
  - Print "Entry" class definition as prefix before entry_dump() or tree_dump() 
  - Style fix on if statement (using blocks). 
  (): Add include files for assert() and svn_xml_escape_attr_cstring()

* subversion/tests/cmdline/svntest/main.py
  (run_entiresdump, run_entriesdump_tree): Move definition of "Entry" class
  into generated code by entries-dump execution. 

Found by: svn-windows-ra buildbot
Reviewed By: danielsh