libarchive: zstd feature check via cc.has_header_symbol() fails with internal (subproject) dependency

[nda-cunh]

Bug report

Line 802 of meson.build says:

we can't use cc.has_function() on dependencies since they might be
internal, so check headers instead

However, the zstd block just below does exactly what this comment warns
against, but with cc.has_header_symbol() instead of cc.has_function():

foreach sym : ['ZSTD_compressStream', 'ZSTD_minCLevel']
  if cc.has_header_symbol(
    'zstd.h',
    sym,
    dependencies: zstd_dep,
  )

cc.has_header_symbol() has the same limitation as cc.has_function():
it rejects internal dependencies in the dependencies: kwarg. This
fails with:

meson.build:347:10: ERROR: Dependencies must be external dependencies

To reproduce

Use zstd via a subproject fallback (i.e. dependency('libzstd', ...)
resolves through fallback:/wrap, not pkg-config/cmake), for example
when zstd isn't installed system-wide and libarchive is built as a
subproject with zstd=enabled.

Environment

• Meson 1.12.0
• libarchive 3.8.9

Suggested fix

Replace the has_header_symbol() calls with a version check, since
Dependency.version() works for both internal and external
dependencies (see liblzma handling a few lines above for a similar
pattern already in this file):

zstd_version = zstd_dep.version()
if zstd_version == 'unknown' or zstd_version.version_compare('>=1.0.0')
  cdata.set('HAVE_ZSTD_compressStream', 1)
endif
if zstd_version == 'unknown' or zstd_version.version_compare('>=1.4.0')
  cdata.set('HAVE_ZSTD_minCLevel', 1)
endif

I've tested this patch locally and it resolves the issue while keeping
zstd statically linked via a subproject.