shelve: refactor shelvestate loading This is a preparatory patch which separates file reading from the minimal validation we have (like turning version into int and checking that this version is supported). The purpose of this patch is to be able to read statefile form simplekeyvaluefile, which is implemented in the following patch.

extdiff: copy back execbit-only changes to the working directory Some tools like BeyondCompare allow the file mode to be changed. The change was previously applied if the content of the file changed (either according to size or mtime), but was not being copied back for a mode-only change. That would seem to indicate handling this in an 'elif' branch, but I opted not to in order to avoid copying back the mode without the content changes when mtime and size are unchanged. (Yes, that's a rare corner case, but all the more reason not to have a subtle difference in behavior.) The only way I can think to handle this undetected change is to set each file in the non-wdir() snapshot to readonly, and check for that attribute (as well as mtime) when deciding to copy back. That would avoid the overhead of copying the whole file when only the mode changed. But a chmod in a diff tool is likely rare. See also affd753ddaf1.

tests: remove regular expression matching for Python 2.6 This effectively reverts 52cca17ac523. Some lines still have (re) due to variable length port numbers. There's not much we can do about that. But at least this change removes most of the ugliness.

branchmap: remove use of buffer() to support Python 2.6 The use of buffer() was added in 7359157b9e46 to support Python 2.6, which we no longer support.