Fuse read_long_string and read_string functionality in an attempt to  increase test code overage. Keep the overhead small for short strings.
Fuse read_long_string and read_string functionality in an attempt to 
increase test code overage. Keep the overhead small for short strings.

* subversion/libsvn_ra_svn/marshal.c
  (read_long_string): drop
  (read_string): handle 32 bit overflows; limit initial string buffer size

Patch by: julianfoad
(with modifications by me)

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1135210 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion