fix: serve dolphin's PAL IPL for australia

Dolphin files the Australian country code under Region::PAL, whose
IPL lives in GC/EUR. Tagged europe alone, --region australia dropped
it and kept the American IPL, which Dolphin never reads for those
discs.

emulators/dolphin-mmjr.yml

@@ -97,7 +97,7 @@ files:
     system: nintendo-gamecube
     required: false
     hle_fallback: true
-    region: [europe]
+    region: [europe, oceania]
     size: 2097152
     crc32: ["4f319f43", "ad1b7f16"]
     validation: [crc32]

emulators/dolphin-mmjr2.yml

@@ -133,7 +133,7 @@ files:
     system: nintendo-gamecube
     required: false
     hle_fallback: true
-    region: [europe]
+    region: [europe, oceania]
     size: 2097152
     crc32: ["4f319f43", "ad1b7f16"]
     validation: [crc32]

emulators/dolphin.yml

@@ -47,7 +47,7 @@ files:
   - name: "IPL.bin"
     path: "dolphin-emu/Sys/GC/EUR/IPL.bin"
     standalone_path: "GC/EUR/IPL.bin"
-    region: [europe]
+    region: [europe, oceania]
     size: 2097152
     required: false
     hle_fallback: true

emulators/ishiiruka.yml

@@ -45,7 +45,7 @@ files:
   - name: "IPL.bin"
     path: "dolphin-emu/Sys/GC/EUR/IPL.bin"
     standalone_path: "GC/EUR/IPL.bin"
-    region: [europe]
+    region: [europe, oceania]
     size: 2097152
     required: false
     hle_fallback: true

emulators/primehack.yml

@@ -43,7 +43,7 @@ files:
 
   - name: "IPL.bin"
     path: "GC/EUR/IPL.bin"
-    region: [europe]
+    region: [europe, oceania]
     size: 2097152
     required: false
     hle_fallback: true

emulators/triforce.yml

@@ -129,7 +129,7 @@ files:
     path: "GC/EUR/IPL_TRI.bin"
     description: "Triforce boot ROM, PAL directory"
     system: sega-triforce
-    region: [europe]
+    region: [europe, oceania]
     size: 2097152
     crc32: "d1883221"
     validation: [crc32]
@@ -205,7 +205,7 @@ files:
   - name: "IPL.bin"
     path: "GC/EUR/IPL.bin"
     description: "GameCube PAL boot ROM"
-    region: [europe]
+    region: [europe, oceania]
     size: 2097152
     required: false
     hle_fallback: true

tests/test_region.py

@@ -401,6 +401,23 @@ class TestFallbackGroups(unittest.TestCase):
         self.assertEqual(region.fallback_groups(groups, self.index, []), [])
 
 
+class AustraliaReadsThePalIpl(unittest.TestCase):
+    """Dolphin files the Australian country code U under Region::PAL
+    (Source/Core/DiscIO/Enums.cpp), whose IPL is GC/EUR. Tagged [europe]
+    alone, `--region australia` dropped it and kept the American one."""
+
+    def test_the_pal_ipl_answers_oceania(self):
+        profiles = common.load_emulator_profiles(
+            os.path.join(os.path.dirname(__file__), "..", "emulators")
+        )
+        for name in ("dolphin", "primehack", "ishiiruka", "triforce"):
+            with self.subTest(profile=name):
+                pal = [f for f in profiles[name]["files"]
+                       if "/EUR/" in str(f.get("path", ""))]
+                self.assertTrue(pal)
+                self.assertTrue(all("oceania" in f.get("region", []) for f in pal))
+
+
 class TestProfileConformance(unittest.TestCase):
     """Every region: value in the repo is a list of canonical slugs."""