From 357caf68c3fbe73ab3a37c1f6a9593a1c22a042e Mon Sep 17 00:00:00 2001
From: Mahesh Arumugam <mahesh@molecula.com>
Date: Thu, 24 Jun 2021 15:10:05 -0700
Subject: [PATCH] Fix percentile query: field is mandatory (should not crash),
 fieldnames can be unquoted

---
 executor.go      | 4 ++--
 executor_test.go | 5 +++++
 pql/ast.go       | 1 +
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/executor.go b/executor.go
index 15d6fb571..449bd69ee 100644
--- a/executor.go
+++ b/executor.go
@@ -1239,10 +1239,10 @@ func (e *executor) executePercentile(ctx context.Context, qcx *Qcx, index string
 	}
 
 	// get field
-	if fieldArg := c.Args["field"]; fieldArg == "" {
+	fieldName, err := c.FirstStringArg("field", "_field")
+	if err != nil {
 		return ValCount{}, errors.New("Percentile(): field required")
 	}
-	fieldName, _, _ := c.StringArg("field")
 
 	// filter call for min & max
 	var filterCall *pql.Call
diff --git a/executor_test.go b/executor_test.go
index 9427914b2..856c2b600 100644
--- a/executor_test.go
+++ b/executor_test.go
@@ -7026,6 +7026,11 @@ func variousQueriesOnPercentiles(t *testing.T, c *test.Cluster) {
 			query:       query,
 			csvVerifier: fmt.Sprintf("%d,1\n", expectedPercentile),
 		})
+		query2 := fmt.Sprintf(`Percentile(field=net_worth, filter=Row(val="foo"), nth=%d)`, nth)
+		tests = append(tests, testCase{
+			query:       query2,
+			csvVerifier: fmt.Sprintf("%d,1\n", expectedPercentile),
+		})
 	}
 
 	for i, tst := range tests {
diff --git a/pql/ast.go b/pql/ast.go
index cb1b78b9e..dddf72812 100644
--- a/pql/ast.go
+++ b/pql/ast.go
@@ -481,6 +481,7 @@ var callInfoByFunc = map[string]callInfo{
 		allowUnknown: false,
 		prototypes: map[string]interface{}{
 			"field":  "",
+			"_field": "",
 			"filter": nil,
 			"nth":    nil,
 		},