test: add more accommodation for DBpedia issues (#2543)

Some further tests failed due to DBPedia issues, this change adds
further accommodation for this.

Test that use external services should be avoided if possible and should
be replaced with the HTTP mocking facilities of the test framework.

test/test_sparql/test_service.py

@@ -27,7 +27,10 @@ def test_service():
         <http://www.w3.org/2000/01/rdf-schema#comment> ?dbpComment .
 
     } }  } limit 2"""
-    results = helper.query_with_retry(g, q)
+    try:
+        results = helper.query_with_retry(g, q)
+    except (RemoteDisconnected, IncompleteRead):
+        pytest.skip("this test uses dbpedia which is down sometimes")
     print(results.vars)
     print(results.bindings)
     assert len(results) == 2
@@ -52,7 +55,10 @@ def test_service_with_bind():
         <http://purl.org/dc/terms/subject> ?subject .
 
     } }  } limit 2"""
-    results = helper.query_with_retry(g, q)
+    try:
+        results = helper.query_with_retry(g, q)
+    except (RemoteDisconnected, IncompleteRead):
+        pytest.skip("this test uses dbpedia which is down sometimes")
     assert len(results) == 2
 
     for r in results:
@@ -88,7 +94,10 @@ def test_service_with_bound_solutions():
         }
         LIMIT 2
         """
-    results = helper.query_with_retry(g, q)
+    try:
+        results = helper.query_with_retry(g, q)
+    except (RemoteDisconnected, IncompleteRead):
+        pytest.skip("this test uses dbpedia which is down sometimes")
     assert len(results) == 2
 
     for r in results:
@@ -111,7 +120,10 @@ def test_service_with_values():
         <http://purl.org/dc/terms/subject> ?subject .
 
     } }  } limit 2"""
-    results = helper.query_with_retry(g, q)
+    try:
+        results = helper.query_with_retry(g, q)
+    except (RemoteDisconnected, IncompleteRead):
+        pytest.skip("this test uses dbpedia which is down sometimes")
     assert len(results) == 2
 
     for r in results:
@@ -128,7 +140,10 @@ def test_service_with_implicit_select():
     {
       values (?s ?p ?o) {(<http://example.org/a> <http://example.org/b> 1) (<http://example.org/a> <http://example.org/b> 2)}
     }} limit 2"""
-    results = helper.query_with_retry(g, q)
+    try:
+        results = helper.query_with_retry(g, q)
+    except (RemoteDisconnected, IncompleteRead):
+        pytest.skip("this test uses dbpedia which is down sometimes")
     assert len(results) == 2
 
     for r in results:
@@ -146,7 +161,10 @@ def test_service_with_implicit_select_and_prefix():
     {
       values (?s ?p ?o) {(ex:a ex:b 1) (<http://example.org/a> <http://example.org/b> 2)}
     }} limit 2"""
-    results = helper.query_with_retry(g, q)
+    try:
+        results = helper.query_with_retry(g, q)
+    except (RemoteDisconnected, IncompleteRead):
+        pytest.skip("this test uses dbpedia which is down sometimes")
     assert len(results) == 2
 
     for r in results:
@@ -164,7 +182,10 @@ def test_service_with_implicit_select_and_base():
     {
       values (?s ?p ?o) {(<a> <b> 1) (<a> <b> 2)}
     }} limit 2"""
-    results = helper.query_with_retry(g, q)
+    try:
+        results = helper.query_with_retry(g, q)
+    except (RemoteDisconnected, IncompleteRead):
+        pytest.skip("this test uses dbpedia which is down sometimes")
     assert len(results) == 2
 
     for r in results:
@@ -212,7 +233,10 @@ def test_simple_not_null():
         VALUES (?s ?p ?o) {(<http://example.org/a> <http://example.org/b> "c")}
     }
 }"""
-    results = helper.query_with_retry(g, q)
+    try:
+        results = helper.query_with_retry(g, q)
+    except (RemoteDisconnected, IncompleteRead):
+        pytest.skip("this test uses dbpedia which is down sometimes")
     assert results.bindings[0].get(Variable("o")) == Literal("c")
 
 
@@ -240,7 +264,10 @@ def test_service_node_types():
     }
     FILTER( ?o IN (<http://example.org/URI>, "Simple Literal", "String Literal"^^xsd:string, "String Language"@en) )
 }"""
-    results = helper.query_with_retry(g, q)
+    try:
+        results = helper.query_with_retry(g, q)
+    except (RemoteDisconnected, IncompleteRead):
+        pytest.skip("this test uses dbpedia which is down sometimes")
 
     expected = freeze_bindings(
         [