shelve: remove useless and incorrect code paths for file access...
shelve: remove useless and incorrect code paths for file access
This patch removes code paths in "shelvedfile.opener()", because:
- explicit "vfs.mkdir()" invocation is useless
"vfs.__call__()" for modes other than "read" creates parent
directory of target file automatically by "util.ensuredirs()".
- mode checking in "except IOError" code path is useless
ENOENT occurs only for "read" mode, because target file is
created forcibly for other modes.
- there is no explicit "return" statement in the code path for
"except IOError" if "mode[0] in 'wa'"
this is incorrect, because None may be returnd unexpectedly,
even though it seems the EEXIST case in the directory creation
race for ".hg/shelved" and is very rare.
this directory creation race is also treated in
"util.ensuredirs()".
