add github workflow to detect duplicates (mdqinc#545)

.github/workflows/check.yml

@@ -0,0 +1,11 @@
+name: Data check
+on:
+  push:
+    branches: [master]
+jobs:
+  duplicates:
+    runs-on: ubuntu-20.04
+    steps:
+    - uses: actions/checkout@v2
+    - run: |
+        python duplicates.py

duplicates.py

@@ -0,0 +1,26 @@
+# SPDX-License-Identifier: Zlib
+
+import difflib
+import sys
+
+CROSS_PLATFORM=False
+
+cdict = {}
+for i, l in enumerate(open("gamecontrollerdb.txt")):
+    l = l.strip()
+    if l.startswith("#") or not l:
+        continue
+
+    c = l.split(",")
+    key = tuple([c[0]]+[ce for ce in c[1:] if "platform:" in ce])
+    if CROSS_PLATFORM:
+        key = c[0]
+
+    if key in cdict:
+        print("Duplicate:", c[1], "at line", i + 1)
+        out = list(difflib.unified_diff(cdict[key], sorted(c), n=0))[3:]
+        out = [o for o in out if not o.startswith("@@")]
+        print("\t", " ".join(out))
+        if not CROSS_PLATFORM:
+            sys.exit(1)
+    cdict[key] = sorted(c)