ninja: Fix the dependency on the VAPI when 'vala_vapi' is used

mesonbuild/backend/ninjabackend.py

@@ -1048,7 +1048,7 @@ int dummy;
                 if hasattr(i, 'fname'):
                     i = i.fname
                 if i.endswith('vala'):
-                    vapiname = dep.name + '.vapi'
+                    vapiname = dep.vala_vapi
                     fullname = os.path.join(self.get_target_dir(dep), vapiname)
                     result.add(fullname)
                     break

test cases/vala/12 custom output/meson.build

@@ -3,7 +3,11 @@ project('valatest', 'c', 'vala')
 glib = dependency('glib-2.0')
 gobject = dependency('gobject-2.0')
 
-library('foo-1.0', 'foo.vala',
-        vala_header: 'foo.h',
-        vala_vapi: 'foo.vapi',
+foo_lib = library('foo-1.0', 'foo.vala',
+                  vala_header: 'foo.h',
+                  vala_vapi: 'foo.vapi',
+                  dependencies: [glib, gobject])
+
+library('bar', 'bar.vala',
+        link_with: [foo_lib],
         dependencies: [glib, gobject])