[stable] Fix #2973: [Reg] error when depending on a subpackages that is already resolved

source/dub/packagemanager.d

@@ -510,23 +510,26 @@ class PackageManager {
 
 		// Before doing a git clone, let's see if the package exists locally
 		if (this.fs.existsDirectory(destination)) {
+			bool isMatch(Package p) {
+				return p.name == name.toString() && p.basePackage.path == destination;
+			}
+
 			// It exists, check if we already loaded it.
 			// Either we loaded it on refresh and it's in PlacementLocation.user,
 			// or we just added it and it's in m_internal.
 			foreach (p; this.m_internal.fromPath)
-				if (p.path == destination)
+				if (isMatch(p))
 					return p;
 			if (this.m_repositories.length)
 				foreach (p; this.m_repositories[PlacementLocation.user].fromPath)
-					if (p.path == destination)
+					if (isMatch(p))
 						return p;
 		} else if (!this.gitClone(repo.remote, gitReference, destination))
 			return null;
 
-		Package result = this.load(destination);
-		if (result !is null)
-			this.addPackages(this.m_internal.fromPath, result);
-		return result;
+		Package p = this.load(destination);
+		if (p is null) return null;
+		return this.addPackagesAndResolveSubPackage(this.m_internal.fromPath, p, name);
 	}
 
 	/**
@@ -1293,7 +1296,7 @@ symlink_exit:
 		return serialized;
 	}
 
-	/// Adds the package and scans for sub-packages.
+	/// Adds the package and its sub-packages.
 	protected void addPackages(ref Package[] dst_repos, Package pack)
 	{
 		// Add the main package.
@@ -1323,6 +1326,29 @@ symlink_exit:
 			}
 		}
 	}
+
+	/// Adds the package and its sub-packages, and returns the added package matching
+	/// the specified name (of the package itself or a sub-package).
+	/// Returns null if the sub-package doesn't exist.
+	private Package addPackagesAndResolveSubPackage(ref Package[] dst_repos, Package pack,
+		in PackageName nameToResolve)
+	in(pack.name == nameToResolve.main.toString(),
+		"nameToResolve must be the added package or one of its sub-packages")
+	{
+		this.addPackages(dst_repos, pack);
+
+		if (nameToResolve.sub.empty)
+			return pack;
+
+		// available sub-packages have been appended
+		foreach_reverse (sp; dst_repos) {
+			if (sp.parentPackage is pack && sp.name == nameToResolve.toString())
+				return sp;
+		}
+
+		logDiagnostic("Sub-package %s not found in parent package", nameToResolve);
+		return null;
+	}
 }
 
 deprecated(OverrideDepMsg)
@@ -1742,9 +1768,8 @@ package struct Location {
 		enforce(
 			p.version_ == vers,
 			format("Package %s located in %s has a different version than its path: Got %s, expected %s",
-				name, path, p.version_, vers));
-		mgr.addPackages(this.fromPath, p);
-		return p;
+				name.main, path, p.version_, vers));
+		return mgr.addPackagesAndResolveSubPackage(this.fromPath, p, name);
 	}
 
 	/**

source/dub/project.d

@@ -557,8 +557,7 @@ class Project {
 						return resolveSubPackage(tmp, subname, true);
 					},
 					(Repository repo) {
-						auto tmp = m_packageManager.loadSCMPackage(basename, repo);
-						return resolveSubPackage(tmp, subname, true);
+						return m_packageManager.loadSCMPackage(dep.name, repo);
 					},
 					(VersionRange range) {
 						// See `dub.recipe.selection : SelectedDependency.fromYAML`
@@ -580,10 +579,9 @@ class Project {
 			if (p is null)
 			{
 				if (!vspec.repository.empty) {
-					p = m_packageManager.loadSCMPackage(basename, vspec.repository);
-					resolveSubPackage(p, subname, false);
+					p = m_packageManager.loadSCMPackage(dep.name, vspec.repository);
 					enforce(p !is null,
-						"Unable to fetch '%s@%s' using git - does the repository and version exists?".format(
+						"Unable to fetch '%s@%s' using git - does the repository and version exist?".format(
 							dep.name, vspec.repository));
 				} else if (!vspec.path.empty && is_desired) {
 					NativePath path = vspec.path;

source/dub/test/dependencies.d

@@ -98,7 +98,7 @@ version "1.0.0"`, PackageFormat.sdl);
     assert(dub.project.hasAllDependencies(), "project has missing dependencies");
     assert(dub.project.getDependency("b", true), "Missing 'b' dependency");
     assert(dub.project.getDependency("c", true), "Missing 'c' dependency");
-    assert(dub.project.getDependency("c", true), "Missing 'd' dependency");
+    assert(dub.project.getDependency("d", true), "Missing 'd' dependency");
     assert(dub.project.getDependency("no", true) is null, "Returned unexpected dependency");
 }
 

source/dub/test/subpackages.d

@@ -38,3 +38,20 @@ unittest
 
     assert(!dub.packageManager().getPackage(PackageName("b:b"), Version("1.1.0")));
 }
+
+// https://github.com/dlang/dub/issues/2973
+unittest
+{
+    scope dub = new TestDub((scope Filesystem root) {
+        root.writeFile(TestDub.ProjectPath ~ "dub.json",
+            `{ "name": "a", "dependencies": { "b:a": "~>1.0" } }`);
+        root.writeFile(TestDub.ProjectPath ~ "dub.selections.json",
+            `{ "fileVersion": 1, "versions": { "b": "1.0.0" } }`);
+        root.writePackageFile("b", "1.0.0",
+            `{ "name": "b", "version": "1.0.0", "subPackages": [ { "name": "a" } ] }`);
+    });
+    dub.loadPackage();
+
+    assert(dub.project.hasAllDependencies(), "project has missing dependencies");
+    assert(dub.project.getDependency("b:a", true), "Missing 'b:a' dependency");
+}