fix issue #177 #178 (#190)

`Get()` and `EachKey()` will panic dealing with invalid parameters in some cases because of array out of bounds. This pr try to fix #177 and #178

parser.go

@@ -267,19 +267,23 @@ func searchKeys(data []byte, keys ...string) int {
 					keyUnesc = ku
 				}
 
-				if equalStr(&keyUnesc, keys[level-1]) {
-					lastMatched = true
-
-					// if key level match
-					if keyLevel == level-1 {
-						keyLevel++
-						// If we found all keys in path
-						if keyLevel == lk {
-							return i + 1
+				if level <= len(keys) {
+					if equalStr(&keyUnesc, keys[level-1]) {
+						lastMatched = true
+
+						// if key level match
+						if keyLevel == level-1 {
+							keyLevel++
+							// If we found all keys in path
+							if keyLevel == lk {
+								return i + 1
+							}
 						}
+					} else {
+						lastMatched = false
 					}
 				} else {
-					lastMatched = false
+					return -1
 				}
 			} else {
 				i--
@@ -490,10 +494,11 @@ func EachKey(data []byte, cb func(int, []byte, ValueType, error), paths ...[]str
 				if len(p) < level+1 || pathFlags&bitwiseFlags[pi+1] != 0 || p[level][0] != '[' || !sameTree(p, pathsBuf[:level]) {
 					continue
 				}
-
-				aIdx, _ := strconv.Atoi(p[level][1 : len(p[level])-1])
-				arrIdxFlags |= bitwiseFlags[aIdx+1]
-				pIdxFlags |= bitwiseFlags[pi+1]
+				if len(p[level]) >= 2 {
+					aIdx, _ := strconv.Atoi(p[level][1 : len(p[level])-1])
+					arrIdxFlags |= bitwiseFlags[aIdx+1]
+					pIdxFlags |= bitwiseFlags[pi+1]
+				}
 			}
 
 			if arrIdxFlags > 0 {

parser_test.go

@@ -814,6 +814,13 @@ var getTests = []GetTest{
 		isFound: true,
 		data:    `1`,
 	},
+	{
+		// Issue #178: Crash in searchKeys
+		desc: `invalid json`,
+		json: `{{{"":`,
+		path: []string{"a", "b"},
+		isFound: false,
+	},
 }
 
 var getIntTests = []GetTest{
@@ -1479,6 +1486,7 @@ func TestEachKey(t *testing.T) {
 		{"arrInt", "[3]"},
 		{"arrInt", "[5]"}, // Should not find last key
 		{"nested"},
+		{"arr", "["}, // issue#177 Invalid arguments
 	}
 
 	keysFound := 0
@@ -1525,6 +1533,8 @@ func TestEachKey(t *testing.T) {
 			if string(value) != `{"a":"test", "b":2, "nested3":{"a":"test3","b":4}, "c": "unknown"}` {
 				t.Error("Should find 9 key", string(value))
 			}
+		case 10:
+			t.Errorf("Found key #10 that should not be found")
 		default:
 			t.Errorf("Should find only 9 keys, got %v key", idx)
 		}