cargo: Load Cargo.lock and subprojects/*.wrap while recursing

In the case the main project has a .wrap file for a cargo subproject,
that subproject's Cargo.lock must be loaded before we can recursively
fetch all its dependencies.

mesonbuild/cargo/interpreter.py

@@ -454,6 +454,8 @@ def _fetch_package(self, package_name: str, api: str) -> T.Tuple[PackageState, b
             return pkg, True
         meson_depname = _dependency_name(package_name, api)
         subdir, _ = self.environment.wrap_resolver.resolve(meson_depname)
+        subprojects_dir = os.path.join(subdir, 'subprojects')
+        self.environment.wrap_resolver.load_and_merge(subprojects_dir, meson_depname)
         manifest = self._load_manifest(subdir)
         pkg = PackageState(manifest)
         self.packages[key] = pkg

mesonbuild/interpreter/interpreter.py

@@ -1286,14 +1286,12 @@ def func_project(self, node: mparser.FunctionNode, args: T.Tuple[str, T.List[str
         self.build.subproject_dir = self.subproject_dir
 
         # Load wrap files from this (sub)project.
-        wrap_mode = WrapMode.from_string(self.coredata.get_option(OptionKey('wrap_mode')))
-        if not self.is_subproject() or wrap_mode != WrapMode.nopromote:
-            subdir = os.path.join(self.subdir, spdirname)
-            r = wrap.Resolver(self.environment.get_source_dir(), subdir, self.subproject, wrap_mode)
-            if self.is_subproject():
-                self.environment.wrap_resolver.merge_wraps(r)
-            else:
-                self.environment.wrap_resolver = r
+        subprojects_dir = os.path.join(self.subdir, spdirname)
+        if not self.is_subproject:
+            wrap_mode = WrapMode.from_string(self.coredata.get_option(OptionKey('wrap_mode')))
+            self.environment.wrap_resolver = wrap.Resolver(self.environment.get_source_dir(), subprojects_dir, self.subproject, wrap_mode)
+        else:
+            self.environment.wrap_resolver.load_and_merge(subprojects_dir, self.subproject)
 
         self.build.projects[self.subproject] = proj_name
         mlog.log('Project name:', mlog.bold(proj_name))

mesonbuild/wrap/wrap.py

@@ -394,14 +394,19 @@ def get_from_wrapdb(self, subp_name: str) -> T.Optional[PackageDefinition]:
         self.add_wrap(wrap)
         return wrap
 
-    def merge_wraps(self, other_resolver: 'Resolver') -> None:
+    def _merge_wraps(self, other_resolver: 'Resolver') -> None:
         for k, v in other_resolver.wraps.items():
             self.wraps.setdefault(k, v)
         for k, v in other_resolver.provided_deps.items():
             self.provided_deps.setdefault(k, v)
         for k, v in other_resolver.provided_programs.items():
             self.provided_programs.setdefault(k, v)
 
+    def load_and_merge(self, subdir: str, subproject: SubProject) -> None:
+        if self.wrap_mode != WrapMode.nopromote:
+            other_resolver = Resolver(self.source_dir, subdir, subproject, self.wrap_mode, self.wrap_frontend, self.allow_insecure, self.silent)
+            self._merge_wraps(other_resolver)
+
     def find_dep_provider(self, packagename: str) -> T.Tuple[T.Optional[str], T.Optional[str]]:
         # Python's ini parser converts all key values to lowercase.
         # Thus the query name must also be in lower case.