Build against glibc-2.43 fails due to -Werror=discarded-qualifiers

[heitbaum]

Describe the bug

../../../lib/hgfs/hgfsEscape.c: In function 'HgfsAddEscapeCharacter':
../../../lib/hgfs/hgfsEscape.c:201:15: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
  201 |       illegal = strchr(HGFS_ILLEGAL_CHARS, bufIn[escapeContext->processedOffset]);
      |               ^
../../../lib/hgfs/hgfsEscape.c: In function 'HgfsIsEscapeSequence':
../../../lib/hgfs/hgfsEscape.c:586:21: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
  586 |          substitute = strchr(HGFS_SUBSTITUTE_CHARS, bufIn[offset - 2]);
      |                     ^
../../../lib/hgfs/hgfsEscape.c:591:18: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
  591 |       substitute = strchr(HGFS_SUBSTITUTE_CHARS, bufIn[offset - 1]);
      |                  ^
../../../lib/hgfs/hgfsEscape.c: In function 'HgfsEscapeUndoComponent':
../../../lib/hgfs/hgfsEscape.c:890:29: error: initialization discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
  890 |          char* substitute = strchr(HGFS_SUBSTITUTE_CHARS, bufIn[offset - 1]);
      |                             ^~~~~~

Reproduction steps

1. Build against glibc-2.43

Expected behavior

Successful compile

Additional context

No response

[pngzhencao-bc]

Thanks for your suggested fix and we'll review.

Could you provide more info about what Linux distro you are using? Is it ubuntu26.04?
We'll create a local test environment to check the fix.

[heitbaum]

Our build server is 26.04 (but the glibc 2.43 is compiled as part of our Cross Compiled Packaging framework.) The issue should be evident when compiling against 2.43.

[heitbaum]

How we do our builds: https://github.com/LibreELEC/LibreELEC.tv/blob/master/tools/docker/README.md

git clone https://github.com/LibreELEC/LibreELEC.tv.git
cd LibreELEC.tv
sed -i -e "s/RUN useradd docker/RUN useradd docker -o -u $(id -u)/" tools/docker/resolute/Dockerfile
docker build --pull -t opvm tools/docker/resolute
docker run --rm --log-driver none -v `pwd`:/build -w /build -it opvm bash

sed -i -e 's/PKG_VERSION=.*/PKG_VERSION="2.43"/' packages/devel/glibc/package.mk
CHANGE_HASH=yes scripts/get glibc
scripts/build open-vm-tools ## This will cause the failure.

To build with 2.42, adjust the packages/devel/glibc/package.mk, then make clean and build the scripts/build open-vm-tools

[pngzhencao-bc]

OK.Thanks for your input and the problem is clear and the fix is straight forward.
Broadcom now has some updated process and document work needed before we could adopt your patch. I'll get back to you once I am clear about the process.