From 6c769aa576699413ce95930eaaf9444d5927b502 Mon Sep 17 00:00:00 2001
From: vvakame <vvakame+dev@gmail.com>
Date: Tue, 27 Nov 2018 15:38:00 +0900
Subject: [PATCH] fix infinit loop in OverlappingFieldsCanBeMerged rule

---
 validator/imported_test.go                    | 16 ++++++++--
 .../rules/overlapping_fields_can_be_merged.go |  4 +++
 validator/spec/Fuzz.spec.yml                  | 29 +++++++++++++++++++
 3 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/validator/imported_test.go b/validator/imported_test.go
index dc2934ac..8139304f 100644
--- a/validator/imported_test.go
+++ b/validator/imported_test.go
@@ -7,6 +7,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"sort"
+	"strconv"
 	"strings"
 	"testing"
 
@@ -20,7 +21,7 @@ import (
 type Spec struct {
 	Name   string
 	Rule   string
-	Schema int
+	Schema string
 	Query  string
 	Errors gqlerror.List
 }
@@ -85,7 +86,18 @@ func runSpec(t *testing.T, schemas []*ast.Schema, deviations []*Deviation, filen
 					}
 				}
 
-				_, err := gqlparser.LoadQuery(schemas[spec.Schema], spec.Query)
+				// idx := spec.Schema
+				var schema *ast.Schema
+				if idx, err := strconv.Atoi(spec.Schema); err != nil {
+					var gqlErr *gqlerror.Error
+					schema, gqlErr = gqlparser.LoadSchema(&ast.Source{Input: spec.Schema, Name: spec.Name})
+					if gqlErr != nil {
+						t.Fatal(err)
+					}
+				} else {
+					schema = schemas[idx]
+				}
+				_, err := gqlparser.LoadQuery(schema, spec.Query)
 				var finalErrors gqlerror.List
 				for _, err := range err {
 					// ignore errors from other rules
diff --git a/validator/rules/overlapping_fields_can_be_merged.go b/validator/rules/overlapping_fields_can_be_merged.go
index 52eab3a2..bb2f1831 100644
--- a/validator/rules/overlapping_fields_can_be_merged.go
+++ b/validator/rules/overlapping_fields_can_be_merged.go
@@ -292,7 +292,11 @@ func (m *overlappingFieldsCanBeMergedManager) collectConflictsBetweenFieldsAndFr
 
 	// (E) Then collect any conflicts between the provided collection of fields
 	// and any fragment names found in the given fragment.
+	baseFragmentSpread := fragmentSpread
 	for _, fragmentSpread := range fragmentSpreads {
+		if fragmentSpread.Name == baseFragmentSpread.Name {
+			continue
+		}
 		m.collectConflictsBetweenFieldsAndFragment(conflicts, areMutuallyExclusive, fieldsMap, fragmentSpread)
 	}
 }
diff --git a/validator/spec/Fuzz.spec.yml b/validator/spec/Fuzz.spec.yml
index a502a614..80c6851d 100644
--- a/validator/spec/Fuzz.spec.yml
+++ b/validator/spec/Fuzz.spec.yml
@@ -3,3 +3,32 @@
   query: '{r{__typename(s:0)}}'
   errors:
     - message: Cannot query field "r" on type "QueryRoot".
+
+- name: 02 - infinit loop occured in OverlappingFieldsCanBeMerged rule
+  schema: |
+    type Query {
+      fieldA: A
+    }
+    type A {
+      s: String
+    }
+  query: |
+    { ...F }
+    fragment F on Query {
+      fieldA { s }
+      ...{
+        ...{
+          ...F
+        }
+        fieldA {
+          ...notExists
+        }
+      }
+    }
+  errors:
+    # from KnownFragmentNames rule
+    - message: Unknown fragment "notExists".
+    - message: Unknown fragment "notExists".
+    - message: Unknown fragment "notExists".
+    # from NoFragmentCycles rule
+    - message: Cannot spread fragment "F" within itself.