bump(main/libxml2): 2.15.0

[TomJo2000]

This took me the better part of a day since it just turned into one thing after the other.
To quickly summarize the things I ran into without inducing madness in the reader:

• I updated the homepage, the previous one was a redirect to the new one.
• Surprise sidequest number 1: The SOVERSION wasn't bumped despite the apparent scheme being Major + Minor since 2.14
  ^{(Put a pin in that...)}
• Doxygen is now required to build any and all docs for libxml2
  • Suprise sidequest number 2: Can't get Autotools to recognize doxygen, alright... Meson it is then.
    Had to get that working by overwriting termux_step_configure() but that worked without issues.
• LZMA support was removed
• Enable Zlib support
• Enable ICU support
• Enable history and readline support for xmllint's shell mode.
• Surprise sidequest number 3: libxml2-python-static is empty now.
  I checked the Arch package, that's just how it is now.
  • Do a sanity check for everything that's in the build directory and what ends up in the packages.
    There is no more gtk-doc, but a shit ton of html ones.
• Surprise sidequest number 4: The xmlcatalog.1 and xmllint.1 manpages are ending up in man instead of man/man1
  This seems like an error in the CMakeLists.txt.
  ^{(Put a pin in that...)}
  https://gitlab.gnome.org/GNOME/libxml2/-/blob/2.15/CMakeLists.txt?ref_type=heads#L570-580

So, that pin from earlier.
@Biswa96 pointed me at this.
https://discourse.gnome.org/t/stepping-down-as-libxml2-maintainer/31398
It looks like Libxml2 is effectively without an upstream maintainer at this time, which partially explains some of the jank I encountered this update cycle.

I also had a look at the Meson summary and tried enabling

-Dthread-alloc=enabled
-Dtls=enabled # (thread local storage, not transport layer security)

It builds with those but throws some compiler warnings.

../src/globals.c:208:13: warning: no previous extern declaration for non-static variable 'xmlFree' [-Wmissing-variable-declarations]
  208 | xmlFreeFunc xmlFree = free;
      |             ^
../src/globals.c:208:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit
  208 | xmlFreeFunc xmlFree = free;
      | ^
../src/globals.c:209:15: warning: no previous extern declaration for non-static variable 'xmlMalloc' [-Wmissing-variable-declarations]
  209 | xmlMallocFunc xmlMalloc = malloc;
      |               ^
../src/globals.c:209:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit
  209 | xmlMallocFunc xmlMalloc = malloc;
      | ^
../src/globals.c:210:15: warning: no previous extern declaration for non-static variable 'xmlMallocAtomic' [-Wmissing-variable-declarations]
  210 | xmlMallocFunc xmlMallocAtomic = malloc;
      |               ^
../src/globals.c:210:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit
  210 | xmlMallocFunc xmlMallocAtomic = malloc;
      | ^
../src/globals.c:211:16: warning: no previous extern declaration for non-static variable 'xmlRealloc' [-Wmissing-variable-declarations]
  211 | xmlReallocFunc xmlRealloc = realloc;
      |                ^
../src/globals.c:211:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit
  211 | xmlReallocFunc xmlRealloc = realloc;
      | ^
../src/globals.c:212:15: warning: no previous extern declaration for non-static variable 'xmlMemStrdup' [-Wmissing-variable-declarations]
  212 | xmlStrdupFunc xmlMemStrdup = xmlPosixStrdup;
      |               ^
../src/globals.c:212:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit
  212 | xmlStrdupFunc xmlMemStrdup = xmlPosixStrdup;
      | ^
5 warnings generated.

And I'm not up for a 5th sidequest today.

[TomJo2000]

Finished the rebuild testing.
Only ran into a couple packages that wouldn't build.

• clamav (doesn't build on current master either)
• libgnustep-base (doesn't build on current master either)
• mlt (fixed in fix(main/libsamplerate): Fix paths in pkgconfig file #26831)

Previous error

Looks like a double prefix error.

CMake Error in src/modules/rubberband/CMakeLists.txt:
  Imported target "PkgConfig::rubberband" includes non-existent path

    "/data/data/com.termux/files/usr/data/data/com.termux/files/usr/include"

  in its INTERFACE_INCLUDE_DIRECTORIES.  Possible reasons include:

  * The path was deleted, renamed, or moved to another location.

  * An install or uninstall procedure did not complete successfully.

  * The installation package was faulty and references files it does not
  provide.

• swift (should be fixed in bump(swift): 6.1.3 to 6.2 #26504)
• webkit2gtk-4.1, webkitgtk-6.0 (NDK 28c related)
• xmlsec (has upstream fix Fix build for LibXML2 > 2.15.0 lsh123/xmlsec#950)

[Biswa96]

• Looks like a double prefix error.

• This fix(main/libsamplerate): Fix paths in pkgconfig file #26831 PR should fix the build error with mlt.

[TomJo2000]

I got xmlsec to build, but I haven't root caused the cause of its build error.
It looks like oldenc changed from xmlChar to const xmlChar, and it's not happy about discarding the const qualifier.

[Biswa96]

It looks like oldenc changed from xmlChar to const xmlChar, and it's not happy about discarding the const qualifier.

That compiler error was fixed in this upstream commit lsh123/xmlsec@ef0e3b5. It will be added to xmlsec 1.3.8 release.

[TomJo2000]

I'll make a backport patch and rip out my non-fix fix.

[robertkirkman]

The problem with webkit2gtk-4.1 and webkitgtk-6.0 is that they have /home/builder/.termux-build/webkit2gtk-4.1/src/Source/ThirdParty/skia/src/core/SkTHash.h:523:32: error: 'pair' is a private member of 'std::pair<unsigned short, SkPDFFont>' with NDK r28c. Unfortunately I don't know how to fix that currently.

[TomJo2000]

Okay so that isn't Libxml2 related then, right?

[robertkirkman]

Correct, however if libxml2 is bumped without rebuilding them I assume the existing builds of them in the packages could stop working.

[TomJo2000]

That only leaves clamav unaccounted for.

[TomJo2000]

• xmlsec just took care of itself d11f24a.

[TomJo2000]

Patching out doxygen from the doc/meson.build was pretty easy, so we don't need to add it to the build container.

[TomJo2000]

All tests I've done on the reverse dependencies for Libxml2 have come up fine,so this should be good to merge.
And if I did miss something I'm sure we'll hear about it very soon seeing as a ton of packages depend on Libxml2 either directly or through one of their dependencies.