[glib: 1/2] meson: Use subproject zlib if "wrap_mode=forcefallback" was specified

[Philip Withnall <pwithnall src gnome org>]

commit 97c7cb0e7141f2bfaaea78d17ff892f8fe8feba7
Author: Seungha Yang <seungha centricular com>
Date:   Mon Feb 22 19:14:43 2021 +0900

    meson: Use subproject zlib if "wrap_mode=forcefallback" was specified
    
    "wrap_mode=forcefallback" would mean that user wants to use dependency
    which was built from our source, instead of system installed one.

 meson.build | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)
---
diff --git a/meson.build b/meson.build
index 8a6dfaede..1de9d929c 100644
--- a/meson.build
+++ b/meson.build
@@ -2004,9 +2004,15 @@ endif
 libm = cc.find_library('m', required : false)
 libffi_dep = dependency('libffi', version : '>= 3.0.0', fallback : ['libffi', 'ffi_dep'])
 
-# Don't use the bundled ZLib sources until we are sure that we can't find it on
-# the system
-libz_dep = dependency('zlib', required : false)
+if get_option('wrap_mode') == 'forcefallback'
+  # Respects "wrap_mode=forcefallback" option
+  libz_dep = subproject('zlib').get_variable('zlib_dep')
+else
+  # Don't use the bundled ZLib sources until we are sure that we can't find it on
+  # the system
+  libz_dep = dependency('zlib', required : false)
+endif
+
 if not libz_dep.found()
   if cc.get_id() != 'msvc' and cc.get_id() != 'clang-cl'
     libz_dep = cc.find_library('z', required : false)