Redirect ambiguous Cummins-Pauli label jumps to the full list of matching curves

lmfdb/modular_curves/main.py

@@ -274,7 +274,13 @@ def modcurve_lmfdb_label(label):
     return lmfdb_label, label_type
 
 def modcurve_jump(info):
-    labels = (info["jump"]).split("*")
+    jump = info["jump"]
+    # Since several modular curves can share the same Cummins-Pauli label,
+    # we redirect to the search results listing all of them when the match
+    # is not unique
+    if CP_LABEL_RE.fullmatch(jump) and db.gps_gl2zhat_fine.count({"CPlabel": jump}) > 1:
+        return redirect(url_for(".index_Q", CPlabel=jump))
+    labels = jump.split("*")
     lmfdb_labels = []
     for label in labels:
         lmfdb_label, label_type = modcurve_lmfdb_label(label)

lmfdb/modular_curves/test_modular_curves.py

@@ -352,11 +352,18 @@ def test_jump(self):
             ('32.1536.41.1175','32.1536.41-32.bz.3.6'),
             ('7B.6.2','7.24.0.b.1'),
             ('4E0-8b','8.12.0.a.1'),
+            ('100A7','100.120.7.a.1'), # CP label matching a unique curve
             ('banana','Error: There is no modular curve in the database')
         ]
         for j,l in jump_set:
             L = self.tc.get("/ModularCurve/Q/?jump=%s" % j,follow_redirects=True)
             assert l in L.get_data(as_text=True)
+        # A CP label shared by several curves redirects to the search results listing all of them
+        L = self.tc.get("/ModularCurve/Q/?jump=113A17",follow_redirects=True)
+        text = L.get_data(as_text=True)
+        assert "Modular curve search results" in text
+        for l in ['113.228.17.a.1','113.228.17.a.2']:
+            assert l in text
 
     def test_related_objects(self):
         for url, friends in [