bug#58835: 28.1; try-complete-file-name-partially modifies text before point

[Anders Munch <ajm@flonidan.dk>]

> May I ask what is the real-life situation where this slash conversion caused you trouble?

Any filename occurring in a text document may potentially be copy-pasted into
some other program.  In most other software that I use, filenames abide by the
platform convention, and a filename occurring in a text document may potentially
be copy-pasted into one of these other programs.  For example, into the address
bar of Windows Explorer, or into a file selection dialog.  For those purposes,
backslashes are the platform standard and frontslashes are not accepted.

For that reason, MS Windows filenames that I keep in text files are written
using backslashes.  When I write part of a file/directory name and use
hippie-expand to help write the rest, then the data that I have already entered
manually is changed, and must be hand-edited back.  Which is frustrating and
time-consuming, and has driven me to no longer use hippie-expand for this.

I'm well aware that GNU Emacs's approach to portability is to make all platforms
pretend they're POSIX, so I wasn't expecting much.  I didn't expect the
expansion to be corrected.  I was just hoping the manually entered text to the
left of point could be left unmangled.

regards, Anders