build: Only use fallback dep for FontConfig when needed/requested

Windows and macOS only optionally requires FontConfig, so:

-Add an option, for Windows and macOS, whether we want to use FontConfig
 on these platforms.  This is ignored on *NIX, where FontConfig will
 always be used.

-We still look for FontConfig first via pkg-config files, and on MSVC
 builds, via looking for its headers and .lib files.  If FontConfig is
 required (or requested) but is not found, we then use the fallback
 dependency for it.

1 files changed, 9 insertions, 2 deletions

diff --git a/meson.build b/meson.build
index 13d9bbff..694c0a19 100644
--- a/meson.build
+++ b/meson.build
@@ -259,8 +259,10 @@ if harfbuzz_dep.found()
   pango_deps += harfbuzz_dep
 endif
 
-fontconfig_dep = dependency('fontconfig', version: fontconfig_req_version, required: false,
-                            fallback: ['fontconfig', 'fontconfig_dep'])
+# Only use FontConfig fallback when required or requested
+fontconfig_required = (host_system != 'windows' and host_system != 'darwin') or get_option('use_fontconfig')
+
+fontconfig_dep = dependency('fontconfig', version: fontconfig_req_version, required: false)
 if fontconfig_dep.found()
   fontconfig_pc = 'fontconfig'
 else
@@ -274,6 +276,11 @@ else
   endif
 endif
 
+if fontconfig_required and not fontconfig_dep.found()
+  fontconfig_dep = dependency('fontconfig', version: fontconfig_req_version,
+                              fallback: ['fontconfig', 'fontconfig_dep'])
+endif
+
 if fontconfig_dep.found()
   pango_deps += fontconfig_dep