fix: drop the atari800 config key aliases

ROM_5200_A, ROM_BASIC_A and six more are atari800.cfg keys, not names
atari800 opens: MatchByName knows only atariosa.rom and its kin
(sysrom.c:278-294), and the keys are config_key since 969907e29. The
twelve labels the scan identifies by CRC32 are found_by: content, and a
platform declaration of a file such an entry accepts by hash, in the
folder the core scans, now meets it: RetroDECK's ROM_BASIC_A answers
atari-basic-rev-a.rom without the alias.

scripts/common.py

@@ -3495,6 +3495,50 @@ def declared_root(config: dict) -> str:
     return root if count / len(roots) > 0.9 else ""
 
 
+def platform_declared_contents(config: dict, db: dict) -> dict[str, set[str]]:
+    """The folders each declared file's content sits in, keyed by its hashes.
+
+    A core that scans a folder and identifies a ROM by its checksum reads a
+    declared file whatever its name: RetroDECK lists atari800's Atari BASIC
+    Rev A as ROM_BASIC_A, and the core takes it by CRC32. Keys are
+    "md5:", "sha1:" and "crc32:" values of the database file the
+    declaration resolves to, each with the declared slot's folder.
+    """
+    prefix = declared_root(config).lower()
+    by_md5 = db.get("indexes", {}).get("by_md5", {})
+    files_db = db.get("files", {})
+    contents: dict[str, set[str]] = {}
+    for system in config.get("systems", {}).values():
+        for fe in system.get("files", []):
+            if fe.get("zipped_file"):
+                continue
+            record = files_db.get((fe.get("sha1") or "").lower())
+            md5 = (fe.get("md5") or "").lower()
+            if record is None and md5 and "," not in md5:
+                sha1 = by_md5.get(md5, "")
+                record = files_db.get(sha1[0] if isinstance(sha1, list) else sha1)
+            if not record:
+                continue
+            slot = sanitize_pack_path(fe.get("destination") or fe.get("name", "")).lower()
+            if prefix and slot.startswith(prefix + "/"):
+                slot = slot[len(prefix) + 1:]
+            folder = slot.rpartition("/")[0]
+            for field in ("md5", "sha1", "crc32"):
+                value = str(record.get(field) or "").lower()
+                if value:
+                    contents.setdefault(f"{field}:{value}", set()).add(folder)
+    return contents
+
+
+def merged_platform_declared_contents(configs: list[dict], db: dict) -> dict[str, set[str]]:
+    """`platform_declared_contents` of several platforms, one index."""
+    merged: dict[str, set[str]] = {}
+    for config in configs:
+        for key, folders in platform_declared_contents(config, db).items():
+            merged.setdefault(key, set()).update(folders)
+    return merged
+
+
 def merged_platform_declarations(
     configs: list[dict], db: dict
 ) -> dict[str, list[tuple[int | None, str]]]:

scripts/cross_reference.py

@@ -35,6 +35,7 @@ from common import (
     get_mame_clone_map,
     list_emulator_profiles,
     list_registered_platforms,
+    merged_platform_declared_contents,
     load_data_dir_registry,
     load_database,
     load_emulator_profiles,
@@ -867,7 +868,8 @@ def _cross_reference_profile(
         # A platform declares files of its BIOS tree: none answers for one
         # the core reads below the save directory.
         in_platform = not save_root and declaration_settles(
-            f, fname, platform_names, effective_path, index.get("folded_slots", frozenset())
+            f, fname, platform_names, effective_path, index.get("folded_slots", frozenset()),
+            index.get("declared_contents"),
         )
 
         if in_platform:
@@ -1318,6 +1320,7 @@ def cross_reference(
     folded_slots: frozenset[str] = frozenset(),
     platform: str = "",
     launcher_layer: LauncherLayer | None = None,
+    declared_contents: dict[str, set[str]] | None = None,
 ) -> dict:
     """Compare emulator profiles against platform declarations.
 
@@ -1355,6 +1358,7 @@ def cross_reference(
         "data_names": data_names,
         "all_declared": all_declared,
         "folded_slots": folded_slots,
+        "declared_contents": declared_contents,
         "bios_dir": db.get("bios_dir"),
         "launcher_candidates": [] if launcher_layer else None,
     }
@@ -1561,6 +1565,13 @@ def main() -> None:
         all_declared=declared_names(args.platforms_dir, selected, db),
         standalone_cores=standalone_cores,
         folded_slots=folded_declared_slots(args.platforms_dir, selected, db),
+        declared_contents=merged_platform_declared_contents(
+            [
+                load_platform_config(name, args.platforms_dir)
+                for name in selected or list_registered_platforms(args.platforms_dir)
+            ],
+            db,
+        ),
         platform=config.get("_key", args.platform) if args.platform else "",
         # What the platform's launchers open, as verify and the builder read it.
         launcher_layer=LauncherLayer(

scripts/validation.py

@@ -606,9 +606,15 @@ def declaration_settles(
     declared_names: Mapping[str, list[tuple[int | None, str]]] | set[str],
     dest: str = "",
     folded_slots: frozenset[str] = frozenset(),
+    declared_contents: Mapping[str, set[str]] | None = None,
 ) -> bool:
     """Whether a platform declaration meets a core's requirement.
 
+    An entry the core finds by content (``found_by: content`` on the entry)
+    is met by any declaration of a file it accepts by hash, in the folder it
+    scans: atari800 takes RetroDECK's ROM_BASIC_A by its CRC32, so its own
+    label for that ROM is not one more file to ship.
+
     A platform declaring the name the core reads has met the requirement
     where the declaration fills the entry's own slot, whose content the slot
     arbitration decides, or elsewhere at a size the core accepts: the builder
@@ -630,6 +636,13 @@ def declaration_settles(
         return True
     slot = sanitize_pack_path(dest or fname).lower()
     directory = slot if dest.endswith("/") else slot.rpartition("/")[0]
+    if declared_contents and file_entry.get("found_by") == "content":
+        for field in ("md5", "sha1", "crc32"):
+            values = file_entry.get(field) or []
+            for value in values if isinstance(values, list) else str(values).split(","):
+                folders = declared_contents.get(f"{field}:{str(value).strip().lower()}")
+                if folders and directory in folders:
+                    return True
     if not dest.endswith("/") and slot in folded_slots:
         return True
     for name in (fname, *file_entry.get("aliases", [])):

scripts/verify.py

@@ -60,6 +60,7 @@ from common import (
     compute_hashes,
     expand_directory_entries,
     platform_declarations,
+    platform_declared_contents,
     group_identical_platforms,
     list_emulator_profiles,
     list_system_ids,
@@ -454,6 +455,7 @@ def _candidate_verdict(
     declared_names: Mapping[str, list[tuple[int | None, str]]] | set[str],
     dest: str = "",
     folded_slots: frozenset[str] = frozenset(),
+    declared_contents: Mapping[str, set[str]] | None = None,
 ) -> str:
     """Whether a profile entry can be a gap, and whether it is settled.
 
@@ -469,7 +471,7 @@ def _candidate_verdict(
     if outside_gap_scope(file_entry, is_standalone):
         return "skip"
     if not include_all and declaration_settles(
-        file_entry, fname, declared_names, dest, folded_slots
+        file_entry, fname, declared_names, dest, folded_slots, declared_contents
     ):
         return "settled"
     return "keep"
@@ -503,6 +505,7 @@ def find_undeclared_files(
     if declared_names is None:
         declared_names = platform_declarations(config, db)
     folded_slots = case_folded_slots(config, declared_names)
+    declared_contents = platform_declared_contents(config, db)
 
     # Whether the builder drops a file whose local copy contradicts its
     # declared hash, which decides if such a copy counts as held here.
@@ -603,6 +606,7 @@ def find_undeclared_files(
                 verdict = _candidate_verdict(
                     f, fname, is_standalone, include_all,
                     {} if save_root else declared_names, dest, folded_slots,
+                    None if save_root else declared_contents,
                 )
                 if verdict == "settled":
                     seen_files.add(seen_key)