[RFC PATCH 5/5] meson: Do not use internal fdt library if user asked for the system one

[Philippe Mathieu-Daudé]

If the user explicitly asked for the system libfdt library, but
the library is not usable (usually too old), we should not silently
default to the internal one.
Respect the user decision, and only default to 'internal' if in
auto mode.

Fixes: fbb4121d592 ("dtc: Convert Makefile bits to meson bits")
Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
BugLink: https://bugs.launchpad.net/qemu/+bug/1907427
Fixes: https://gitlab.com/qemu-project/qemu/-/issues/255
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/meson.build b/meson.build
index 0b41ff41188..1ffb4bccdb2 100644
--- a/meson.build
+++ b/meson.build
@@ -1612,7 +1612,7 @@
        int main(void) { fdt_check_full(NULL, 0); return 0; }''',
          dependencies: fdt)
       fdt_opt = 'system'
-    elif have_internal
+    elif have_internal and fdt_opt in ['enabled', 'auto']
       fdt_opt = 'internal'
     else
       fdt_opt = 'disabled'
-- 
2.26.3