test(subdomain-gw): content validation before redirect

This adds test for redirect scenario from subdomain root domain to
$cid.ipfs.example.com subdomain when provided content path is invalid.

Some http clients such as web browsers force-lowercase domain names,
and we want to ensure the error happens before redirect and includes
original (case-sensitive) content path.

#6096 (comment)

License: MIT
Signed-off-by: Marcin Rataj <[email protected]>

test/sharness/t0114-gateway-subdomains.sh

@@ -300,6 +300,13 @@ test_hostname_gateway_response_should_contain \
   "http://127.0.0.1:$GWAY_PORT/ipfs/$CIDv1" \
   "Location: http://$CIDv1.ipfs.example.com/"
 
+# error message should include original CID
+# (and it should be case-sensitive, as we can't assume everyone uses base32)
+test_hostname_gateway_response_should_contain \
+  "request for example.com/ipfs/{InvalidCID} produces useful error before redirect" \
+  "example.com" \
+  "http://127.0.0.1:$GWAY_PORT/ipfs/QmInvalidCID" \
+  'invalid path \"/ipfs/QmInvalidCID\"'
 
 test_hostname_gateway_response_should_contain \
   "request for example.com/ipfs/{CIDv0} produces redirect to {CIDv1}.ipfs.example.com" \
@@ -313,6 +320,8 @@ test_expect_success "request for http://example.com/ipfs/{CID} with X-Forwarded-
   test_should_contain \"Location: https://$CIDv1.ipfs.example.com/\" response
 "
 
+
+
 # example.com/ipns/<libp2p-key>
 
 test_hostname_gateway_response_should_contain \