Fix empty name on manually installed platforms without platform.txt

arduino/cores/packagemanager/loader.go

@@ -320,7 +320,14 @@ func (pm *PackageManager) loadPlatformRelease(platform *cores.PlatformRelease, p
 	}
 
 	if platform.Platform.Name == "" {
-		platform.Platform.Name = platform.Properties.Get("name")
+		if name, ok := platform.Properties.GetOk("name"); ok {
+			platform.Platform.Name = name
+		} else {
+			// If the platform.txt file doesn't exist for this platform and it's not in any
+			// package index there is no way of retrieving its name, so we build one using
+			// the available information, that is the packager name and the architecture.
+			platform.Platform.Name = fmt.Sprintf("%s-%s", platform.Platform.Package.Name, platform.Platform.Architecture)
+		}
 	}
 
 	// Create programmers properties

test/test_core.py

@@ -648,3 +648,30 @@ def test_core_list_deprecated_platform_with_installed_json(run_command, httpserv
     platforms = json.loads(result.stdout)
     assert len(platforms) == 1
     assert platforms[0]["deprecated"]
+
+
+def test_core_list_platform_without_platform_txt(run_command, data_dir):
+    assert run_command("update")
+
+    # Verifies no core is installed
+    res = run_command("core list --format json")
+    assert res.ok
+    cores = json.loads(res.stdout)
+    assert len(cores) == 0
+
+    # Simulates creation of a new core in the sketchbook hardware folder
+    # without a platforms.txt
+    test_boards_txt = Path(__file__).parent / "testdata" / "boards.local.txt"
+    boards_txt = Path(data_dir, "hardware", "some-packager", "some-arch", "boards.txt")
+    boards_txt.parent.mkdir(parents=True, exist_ok=True)
+    boards_txt.touch()
+    boards_txt.write_bytes(test_boards_txt.read_bytes())
+
+    # Verifies no core is installed
+    res = run_command("core list --format json")
+    assert res.ok
+    cores = json.loads(res.stdout)
+    assert len(cores) == 1
+    core = cores[0]
+    assert core["id"] == "some-packager:some-arch"
+    assert core["name"] == "some-packager-some-arch"