Honour simple_templates everywhere in referenceFS

fsspec/implementations/reference.py

@@ -615,6 +615,9 @@ class ReferenceFileSystem(AsyncFileSystem):
     Reference dict format:
     {path0: bytes_data, path1: (target_url, offset, size)}
     https://github.com/fsspec/kerchunk/blob/main/README.md
+
+    simple_references: if True (default), no jinja interpreting is done,
+        which is the safe option.
     """
 
     protocol = "reference"
@@ -1056,6 +1059,8 @@ def _process_templates(self, tmp):
 
     def _process_gen(self, gens):
         out = {}
+        if self.simple_templates:
+            return out
         for gen in gens:
             dimension = {
                 k: (

fsspec/implementations/tests/test_reference.py

@@ -365,7 +365,12 @@ def test_spec1_gen_variants():
                 },
             ],
         }
-        fsspec.filesystem("reference", fo=missing_length_spec, target_protocol="http")
+        fsspec.filesystem(
+            "reference",
+            fo=missing_length_spec,
+            simple_templates=False,
+            target_protocol="http",
+        )
 
     with pytest.raises(ValueError):
         missing_offset_spec = {
@@ -380,7 +385,12 @@ def test_spec1_gen_variants():
                 },
             ],
         }
-        fsspec.filesystem("reference", fo=missing_offset_spec, target_protocol="http")
+        fsspec.filesystem(
+            "reference",
+            simple_templates=False,
+            fo=missing_offset_spec,
+            target_protocol="http",
+        )
 
     url_only_gen_spec = {
         "version": 1,
@@ -394,7 +404,12 @@ def test_spec1_gen_variants():
         ],
     }
 
-    fs = fsspec.filesystem("reference", fo=url_only_gen_spec, target_protocol="http")
+    fs = fsspec.filesystem(
+        "reference",
+        simple_templates=False,
+        fo=url_only_gen_spec,
+        target_protocol="http",
+    )
     assert fs.references == {
         "gen_key0": ["http://server.domain/path_0"],
         "gen_key1": ["http://server.domain/path_1"],
@@ -961,3 +976,21 @@ def test_parquet_no_references(m):
     lz.flush()
 
     assert arr[...].tolist() == 1  #  scalar, equal to fill value
+
+
+def test_no_default_jinja_execution():
+    pytest.importorskip("jinja2")
+    manifest = {
+        "version": 1,
+        "templates": {},
+        "refs": {},
+        "gen": [
+            {"key": "{{ 1 / 0 }}", "url": "file:///dev/null", "dimensions": {"i": [0]}}
+        ],
+    }
+
+    # no error - not evaluated
+    fsspec.filesystem("reference", fo=manifest)
+
+    with pytest.raises(ZeroDivisionError):
+        fsspec.filesystem("reference", fo=manifest, simple_templates=False)