Remove cid-based shortcut

This optimization should be handled by the index, not the scan code.  It also produces undesirable errors which have been corrected in this commit.

planner/commit.go

@@ -165,22 +165,6 @@ func (n *dagScanNode) Next() (bool, error) {
 	if len(n.queuedCids) > 0 {
 		currentCid = n.queuedCids[0]
 		n.queuedCids = n.queuedCids[1:(len(n.queuedCids))]
-	} else if n.parsed.Cid.HasValue() && !n.parsed.DocKey.HasValue() {
-		if n.visitedNodes[n.parsed.Cid.Value()] {
-			// If the requested cid has been visited, we are done and should return false
-			return false, nil
-		}
-
-		cid, err := cid.Decode(n.parsed.Cid.Value())
-		if err != nil {
-			return false, err
-		}
-
-		if hasCid, err := store.Has(n.p.ctx, cid); !hasCid || err != nil {
-			return false, err
-		}
-
-		currentCid = &cid
 	} else {
 		cid, err := n.fetcher.FetchNext()
 		if err != nil || cid == nil {

tests/integration/query/commits/with_cid_test.go

@@ -102,7 +102,7 @@ func TestQueryCommitsWithInvalidCid(t *testing.T) {
 				}`,
 			},
 		},
-		ExpectedError: "encoding/hex: invalid byte:",
+		Results: []map[string]any{},
 	}
 
 	executeTestCase(t, test)
@@ -128,7 +128,7 @@ func TestQueryCommitsWithInvalidShortCid(t *testing.T) {
 				}`,
 			},
 		},
-		ExpectedError: "length greater than remaining number of bytes in buffer",
+		Results: []map[string]any{},
 	}
 
 	executeTestCase(t, test)