bugfixes: collection of fixes to bugs found while fuzzing

go/test/endtoend/vtgate/queries/aggregation/aggregation_test.go

@@ -440,6 +440,9 @@ func TestBuggyQueries(t *testing.T) {
 		"[[NULL NULL INT64(3) NULL NULL INT64(3)] "+
 			"[INT32(100) DECIMAL(300) INT64(3) INT32(100) DECIMAL(300) INT64(3)] "+
 			"[INT32(200) DECIMAL(600) INT64(3) INT32(200) DECIMAL(600) INT64(3)]]")
+
+	mcmp.Exec("select /*vt+ PLANNER=gen4 */sum(tbl1.a), min(tbl0.b) from t10 as tbl0, t10 as tbl1 left join t10 as tbl2 on tbl1.a = tbl2.a and tbl1.b = tbl2.k")
+	mcmp.Exec("select /*vt+ PLANNER=gen4 */count(*) from t10 left join t10 as t11 on t10.a = t11.b where t11.a")
 }
 
 func TestMinMaxAcrossJoins(t *testing.T) {

go/test/endtoend/vtgate/queries/misc/misc_test.go

@@ -303,3 +303,13 @@ func TestPrepareStatements(t *testing.T) {
 	_, err = mcmp.ExecAllowAndCompareError("deallocate prepare prep_art")
 	assert.ErrorContains(t, err, "VT09011: Unknown prepared statement handler (prep_art) given to DEALLOCATE PREPARE")
 }
+
+func TestBuggyOuterJoin(t *testing.T) {
+	// We found a couple of inconsistencies around outer joins, adding these tests to stop regressions
+	mcmp, closer := start(t)
+	defer closer()
+
+	mcmp.Exec("insert into t1(id1, id2) values (1,2), (42,5), (5, 42)")
+
+	mcmp.Exec("select t1.id1, t2.id1 from t1 left join t1 as t2 on t2.id1 = t2.id2")
+}

go/vt/vtgate/engine/filter.go

@@ -67,11 +67,8 @@ func (f *Filter) TryExecute(ctx context.Context, vcursor VCursor, bindVars map[s
 		if err != nil {
 			return nil, err
 		}
-		intEvalResult, err := evalResult.Value().ToInt64()
-		if err != nil {
-			return nil, err
-		}
-		if intEvalResult == 1 {
+
+		if evalResult.ToBoolean() {
 			rows = append(rows, row)
 		}
 	}

go/vt/vtgate/engine/projection.go

@@ -129,7 +129,7 @@ func (p *Projection) GetFields(ctx context.Context, vcursor VCursor, bindVars ma
 		return nil, err
 	}
 	env := evalengine.NewExpressionEnv(ctx, bindVars, vcursor)
-	qr.Fields, err = p.evalFields(env, nil)
+	qr.Fields, err = p.evalFields(env, qr.Fields)
 	if err != nil {
 		return nil, err
 	}

go/vt/vtgate/planbuilder/operators/joins.go

@@ -54,7 +54,7 @@ func AddPredicate(
 	case deps.IsSolvedBy(TableID(join.GetRHS())):
 		// if we are dealing with an outer join, always start by checking if this predicate can turn
 		// the join into an inner join
-		if !join.IsInner() && canConvertToInner(ctx, expr, TableID(join.GetRHS())) {
+		if !joinPredicates && !join.IsInner() && canConvertToInner(ctx, expr, TableID(join.GetRHS())) {
 			join.MakeInner()
 		}
 

go/vt/vtgate/planbuilder/testdata/from_cases.json

@@ -6370,5 +6370,83 @@
     "query": "select missing_column from unsharded, unsharded_tab",
     "v3-plan": "VT03019: column missing_column not found",
     "gen4-plan": "Column 'missing_column' in field list is ambiguous"
+  },
+  {
+    "comment": "join predicate only depending on the RHS should not turn outer join into inner join",
+    "query": "select t1.id1, t2.id1 from t1 left join t1 as t2 on t2.id1 = t2.id2",
+    "v3-plan": {
+      "QueryType": "SELECT",
+      "Original": "select t1.id1, t2.id1 from t1 left join t1 as t2 on t2.id1 = t2.id2",
+      "Instructions": {
+        "OperatorType": "Join",
+        "Variant": "LeftJoin",
+        "JoinColumnIndexes": "L:0,R:0",
+        "TableName": "t1_t1",
+        "Inputs": [
+          {
+            "OperatorType": "Route",
+            "Variant": "Scatter",
+            "Keyspace": {
+              "Name": "zlookup_unique",
+              "Sharded": true
+            },
+            "FieldQuery": "select t1.id1 from t1 where 1 != 1",
+            "Query": "select t1.id1 from t1",
+            "Table": "t1"
+          },
+          {
+            "OperatorType": "Route",
+            "Variant": "Scatter",
+            "Keyspace": {
+              "Name": "zlookup_unique",
+              "Sharded": true
+            },
+            "FieldQuery": "select t2.id1 from t1 as t2 where 1 != 1",
+            "Query": "select t2.id1 from t1 as t2 where t2.id1 = t2.id2",
+            "Table": "t1"
+          }
+        ]
+      },
+      "TablesUsed": [
+        "zlookup_unique.t1"
+      ]
+    },
+    "gen4-plan": {
+      "QueryType": "SELECT",
+      "Original": "select t1.id1, t2.id1 from t1 left join t1 as t2 on t2.id1 = t2.id2",
+      "Instructions": {
+        "OperatorType": "Join",
+        "Variant": "LeftJoin",
+        "JoinColumnIndexes": "L:0,R:0",
+        "TableName": "t1_t1",
+        "Inputs": [
+          {
+            "OperatorType": "Route",
+            "Variant": "Scatter",
+            "Keyspace": {
+              "Name": "zlookup_unique",
+              "Sharded": true
+            },
+            "FieldQuery": "select t1.id1 from t1 where 1 != 1",
+            "Query": "select t1.id1 from t1",
+            "Table": "t1"
+          },
+          {
+            "OperatorType": "Route",
+            "Variant": "Scatter",
+            "Keyspace": {
+              "Name": "zlookup_unique",
+              "Sharded": true
+            },
+            "FieldQuery": "select t2.id1 from t1 as t2 where 1 != 1",
+            "Query": "select t2.id1 from t1 as t2 where t2.id1 = t2.id2",
+            "Table": "t1"
+          }
+        ]
+      },
+      "TablesUsed": [
+        "zlookup_unique.t1"
+      ]
+    }
   }
 ]