fix: a platform's own build answers its core name

Recalbox compiles uae4all from Chips-fr/uae4all-rpi, a libretro core, while RetroPie's uae4all package is the standalone uae4all2. A profile whose built_by names the platform now wins the name there, and a bare key match still decides everywhere else.

scripts/common.py

@@ -2245,10 +2245,22 @@ def resolve_platform_cores(
     elif isinstance(cores_config, list):
         core_set = {str(c) for c in cores_config}
         index = upstream_profile_index(profiles)
+        platform = str(config.get("_key") or "")
+
+        def designated(name: str) -> str | None:
+            # A build the platform compiles itself (built_by) is what its
+            # name means there: Recalbox's uae4all is Chips-fr/uae4all-rpi,
+            # RetroPie's the standalone uae4all2 under the same name.
+            own = sorted(
+                p for p in index.get(name, ())
+                if platform and platform in (profiles[p].get("built_by") or [])
+            )
+            return own[0] if own else preferred_profile(index, name)
+
         result = {
             profile
             for c in core_set
-            if (profile := preferred_profile(index, c)) is not None
+            if (profile := designated(c)) is not None
         }
         # A name the platform launches both ways designates its libretro
         # build too. Batocera, Recalbox and RetroBat run pcsx2 standalone and

tests/test_batocera_cores.py

@@ -141,5 +141,22 @@ class DualModeNameReachesTheLibretroBuild(unittest.TestCase):
         self.assertEqual(resolve_platform_cores(config, profiles), {"pcsx2", "lrps2"})
 
 
+class APlatformsOwnBuildWinsItsName(unittest.TestCase):
+    """Recalbox's uae4all is the libretro uae4all-rpi it compiles, RetroPie's
+    the standalone uae4all2: one name, two programs."""
+
+    def test_built_by_beats_the_key_match_for_that_platform_only(self):
+        from common import resolve_platform_cores
+
+        profiles = {
+            "uae4all": {"type": "standalone", "cores": ["uae4all"]},
+            "uae4all-rpi": {"type": "libretro", "cores": ["uae4all"], "built_by": ["recalbox"]},
+        }
+        recalbox = {"_key": "recalbox", "cores": ["uae4all"]}
+        retropie = {"_key": "retropie", "cores": ["uae4all"]}
+        self.assertEqual(resolve_platform_cores(recalbox, profiles), {"uae4all-rpi"})
+        self.assertEqual(resolve_platform_cores(retropie, profiles), {"uae4all"})
+
+
 if __name__ == "__main__":
     unittest.main()