[tex-k] texk/web2c/configure at 73540 breaks the build of web2c when using --disable-xetex

[balducci at units.it]

hello

since quite a bit (2017) I use to build regularly the web2c
distribution from svn and almost never had any problem.

I also maintain locally on my system the kpathsea library (installed
separately from web2c) and use --with-system-kpathsea when building
web2c.

However, after the changes to texk/web2c/configure in revision 73540
my build fails almost immediately with a bunch of link errors for
tangleboot due to a missing -lkpathsea in the link command.

After debugging, the problem seems to be that in revision 73540 of
texk/web2c/configure the test for pkg-config (and, BTW, fontconfig
includes/libs) has ended up inside the scope of a test for enabling xetex:

                        +---------------------------------------------------+
  +-------------------- | line 24334: if test "x$enable_xetex" = xyes; then |
  |                     +---------------------------------------------------+
  |                       :
  |                       :
  |                       :
  |                     +---------------------------------------------------+
  |                     | line 24371: if test -n "$ac_tool_prefix"; then    | -+
  |                     +---------------------------------------------------+  |
  |                       :                                                    |
  | xetex enabling code   : pkg-config probing code                            |
  |                       :                                                    |
  |                     +---------------------------------------------------+  |
  |                     | line 24473: fi                                    | -+
  |                     +---------------------------------------------------+
  |                       :
  |                       :
  |                       :
  |                     +---------------------------------------------------+
  +-------------------- | line 24561: fi                                    |
                        +---------------------------------------------------+

This was not the case with previous revision (73472).

Since I run the build with --disable-xetex, pkg-config is not probed
and the test for system wide kpathsea (which uses pkg-config and is
performed downstream in texk/web2c/configure) fails, leading to the
link errors mentioned above.

As a check, if I run the build of web2c with --enable-xetex, then the
link errors go away.

Also, I can workaround the link errors if I run the build with
   export PKG_CONFIG=/usr/bin/pkg-config
(and --disable-xetex)

As an additional check, this patch also fixes the build with
--disable-xetex:

diff -c ./configure.MOVE_FI_UPWARDS ./configure
*** ./configure.MOVE_FI_UPWARDS	Fri Jan 24 15:39:58 2025
--- ./configure	Fri Jan 24 15:39:58 2025
***************
*** 24368,24373 ****
--- 24368,24374 ----
  
  fi
  
+ fi
    if test -n "$ac_tool_prefix"; then
    # Extract the first word of "${ac_tool_prefix}pkg-config", so it can be a program name with args.
  set dummy ${ac_tool_prefix}pkg-config; ac_word=$2
***************
*** 24558,24564 ****
  fi
  
  fi
- fi
   if test "x$kpse_cv_have_ApplicationServices" = xyes; then
    XETEX_MACOSX_TRUE=
    XETEX_MACOSX_FALSE='#'
--- 24559,24564 ----

It seems to me that probing for pkg-config (and fontconfig
includes/libs) should not be done only when xetex is enabled (see
above), no?

Or am I missing some blatant point here?

Thanks in advance for any feedback and thank you very much for your
valuable work

ciao
-gabriele