"C:\foo" names the root of drive C, but "C:foo" names foo relative to
whatever the current directory on C happens to be. Classifying the
second as absolute means it is resolved from a root it does not name.
Rejecting absolute names was also the only thing keeping a
drive-relative name out of a patch, so is_safe_patch_path() now refuses
a colon itself. A colon never appears in a Windows file name, since
"file:stream" names an alternate data stream of "file" rather than a
file of that name.
Shannon Booth
e0ae942bae