From 3c5617faed9d63956132ce883aa5e207412abe41 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maxime=20Soul=C3=A9?= <btik-git@scoubidou.com>
Date: Mon, 21 Sep 2020 17:22:36 +0200
Subject: [PATCH] Avoid a conflict between possible named params & map as param

maybeExpandNamedQuery() now checks time.Time & driver.Valuer types
first before trying to check if the passed param is a map of named
params.

It allows to pass a map[string]struct{}{} type implementing
driver.Valuer without suffering any conflict with a map of named
params.

Closes #423
---
 gorp.go | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/gorp.go b/gorp.go
index fc654567..0ca714ff 100644
--- a/gorp.go
+++ b/gorp.go
@@ -203,12 +203,21 @@ func extractExecutorAndContext(e SqlExecutor) (executor, context.Context) {
 // as input to a named query.  If so, it rewrites the query to use
 // dialect-dependent bindvars and instantiates the corresponding slice of
 // parameters by extracting data from the map / struct.
-// If not, returns the input values unchanged.
+// If not or if the first arg is a time.Time or implements
+// driver.Valuer, returns the input values unchanged.
 func maybeExpandNamedQuery(m *DbMap, query string, args []interface{}) (string, []interface{}) {
-	var (
-		arg    = args[0]
-		argval = reflect.ValueOf(arg)
-	)
+	arg := args[0]
+
+	switch arg.(type) {
+	case time.Time:
+		// time.Time is driver.Value
+		return query, args
+	case driver.Valuer:
+		// driver.Valuer will be converted to driver.Value.
+		return query, args
+	}
+
+	argval := reflect.ValueOf(arg)
 	if argval.Kind() == reflect.Ptr {
 		argval = argval.Elem()
 	}
@@ -221,14 +230,6 @@ func maybeExpandNamedQuery(m *DbMap, query string, args []interface{}) (string,
 	if argval.Kind() != reflect.Struct {
 		return query, args
 	}
-	if _, ok := arg.(time.Time); ok {
-		// time.Time is driver.Value
-		return query, args
-	}
-	if _, ok := arg.(driver.Valuer); ok {
-		// driver.Valuer will be converted to driver.Value.
-		return query, args
-	}
 
 	return expandNamedQuery(m, query, argval.FieldByName)
 }