patch command incorrectly capitalizes filenames that live on external USB flash drives

[Jason Gross]

By the way, when I run the same script on the same flash drive from WSL, it
works fine, and does not capitalize the filename.  So this does seem to be
a cygwin-patch specific issue...

On Wed, May 13, 2020 at 8:31 PM Jason Gross <jasongross9@gmail.com> wrote:

> Sorry for the late reply; I can see replies to my messages at
> https://cygwin.com/pipermail/cygwin/2020-April/244660.html, but
> somehow I'm not receiving them in Gmail.  I've tried (re?)subscribing
> to the cygwin mailing list, hopefully this fixes the problem.
>
> Thomas Wolff wrote:
> > You are throwing a puzzle into the mailing list and if you are lucky,
> > someone may like to solve it.
> > But perhaps: can you try to minimize your test case, please.
> > Something like: touch Makefile; ls (if that's it).
>
> I think there's some sort of misconception here.  touch and cat create
> correctly capitalized files, and sed -i doesn't change capitalization,
> even on my FAT32 drive.  patch is the only command I've found so far
> which capitalizes filenames when modifying files.  I can try to dig
> into the source code of patch and figure out a minimal C program that
> breaks casing on files, but, come on, the fact that patch seems to
> capitalize the file name of every file it modifies, and no other
> utility does this, that seems like a pretty minimal test-case to me.
> And anyway, the cygwin patch sources (version 2.7.4) are impossible to
> compile, because safe.c can't find sys/resource.h and passing
> -I/usr/include via CFLAGS hits an internal bug in patch's configure
> script (search.h: present but cannot be compiled; sys/timeb.h: present
> but cannot be compiled; fcntl.h: present but cannot be compiled).  (I've
> emailed
> bug-patch@gnu.org as requested by the configure script, but so far
> https://lists.gnu.org/archive/html/bug-patch/ isn't showing anything
> newer than January.)
>
> Brian Inglis wrote:
> > That might be expected with FAT32, which is normally the default format
> for
> > flash drives, for maximum compatibility with microcontrollers, which may
> not
> > create VFAT Long File Names when file names are <= 8.3, so they appear
> as upper
> > case.
>
> This does not explain why `ls` displays "Makefile" as "Makefile"
> before I run `patch`, but displays the filename as "MAKEFILE" after I
> run `patch`.  Nor does it explain why this happens to patch-modified
> files, but not to files modified via sed -i.
>
> Marco Atzeri wrote:
> > use a flash driver with NTFS and check the difference
>
> Indeed, I can confirm that this issue occurs when it's FAT or FAT32,
> and does not occur under NTFS nor exFAT.
>
> > I doubt it is a patch issue
>
> Do you have another utility that you suggest I try that you think will
> display the same problem as patch?  So far, `| tee -a`, `sed -i`,
> `touch`, `>`, and `>>` all do not display this issue, while `patch`
> does.
>
>
> -Jason
>
>
>
>
> On Tue, Apr 28, 2020 at 3:27 PM Jason Gross <jasongross9@gmail.com> wrote:
> >
> > Consider the following script in foo.sh:
> > ```
> > #!/usr/bin/env bash
> >
> > set -ex
> >
> > cd "$1"
> > rm -rf foo
> > mkdir foo
> > cd foo
> > cat > Makefile <<EOF
> > a
> > b
> > c
> > d
> > e
> > EOF
> > cat > diff <<EOF
> > diff --git a/Makefile b/Makefile
> > index 9405325..86d2f8c 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -1,5 +1,5 @@
> >  a
> >  b
> > -c
> > +ccc
> >  d
> >  e
> > EOF
> > patch -p1 -i ./diff
> > ls
> > ```
> >
> > If I run `./foo.sh /cygdrive/c/`, I get, as expected,
> > ```
> > + cd /cygdrive/c/
> > + rm -rf foo
> > + mkdir foo
> > + cd foo
> > + cat
> > + cat
> > + patch -p1 -i ./diff
> > patching file Makefile
> > + ls
> > diff  Makefile
> > ```
> >
> > If I instead run `./foo.sh /cygdrive/h/`, I get
> > ```
> > + cd /cygdrive/h/
> > + rm -rf foo
> > + mkdir foo
> > + cd foo
> > + cat
> > + cat
> > + patch -p1 -i ./diff
> > patching file Makefile
> > + ls
> > diff  MAKEFILE
> > ```
> >
> > My C drive is an internal SSD (NTFS), my H drive is an external flash
> > drive (FAT32).  I installed cygwin with the commands:
> > ```
> > powershell -Command "(New-Object
> > Net.WebClient).DownloadFile('http://www.cygwin.com/setup-x86_64.exe',
> > 'setup-x86_64.exe')"
> > SET CYGMIRROR=http://mirror.easyname.at/cygwin
> > SET CYGROOT=H:\cygwin64
> > SET CYGCACHE=%CYGROOT%\var\cache\setup
> > setup-x86_64.exe -qnNdO -R %CYGROOT% -l %CYGCACHE% -s %CYGMIRROR% -P
> > rsync -P patch -P diffutils -P make -P unzip -P m4 -P findutils -P
> > time -P wget -P curl -P git -P
> >
> mingw64-x86_64-binutils,mingw64-x86_64-gcc-core,mingw64-x86_64-gcc-g++,mingw64-x86_64-pkg-config,mingw64-x86_64-windows_default_manifest
> > -P
> mingw64-x86_64-headers,mingw64-x86_64-runtime,mingw64-x86_64-pthreads,mingw64-x86_64-zlib
> > -P python3
> > ```
> >
> > Running `patch -v` says `GNU patch 2.7.4`.  Note that this happens
> > regardless of whether I install cygwin itself on my external flash
> > drive or on my internal HD.
> >
> > This came up when trying to run `opam install findlib` (which fails
> > when the home directory is on an external USB drive).
> >
> > -Jason
>