From c1badc05106a54f81040459a9e58e4730138cf9d Mon Sep 17 00:00:00 2001
From: "Crom (Thibaut CHARLES)" <CromFr@gmail.com>
Date: Thu, 14 Dec 2017 00:24:49 +0100
Subject: [PATCH] Added common.IsUniqueConstraintViolationErr

---
 .../dendrite/clientapi/auth/storage/accounts/storage.go  | 9 +++------
 src/github.com/matrix-org/dendrite/common/sql.go         | 8 ++++++++
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/github.com/matrix-org/dendrite/clientapi/auth/storage/accounts/storage.go b/src/github.com/matrix-org/dendrite/clientapi/auth/storage/accounts/storage.go
index addb6a9d2..e88942e34 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/auth/storage/accounts/storage.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/auth/storage/accounts/storage.go
@@ -24,7 +24,7 @@ import (
 	"github.com/matrix-org/gomatrixserverlib"
 	"golang.org/x/crypto/bcrypt"
 	// Import the postgres database driver.
-	"github.com/lib/pq"
+	_ "github.com/lib/pq"
 )
 
 // Database represents an account database
@@ -128,11 +128,8 @@ func (d *Database) CreateAccount(
 		return nil, err
 	}
 	if err := d.profiles.insertProfile(ctx, localpart); err != nil {
-		if err, ok := err.(*pq.Error); ok {
-			if err.Code.Class() == "23" {
-				// 23 => unique_violation => Account already exists
-				return nil, nil
-			}
+		if common.IsUniqueConstraintViolationErr(err) {
+			return nil, nil
 		}
 		return nil, err
 	}
diff --git a/src/github.com/matrix-org/dendrite/common/sql.go b/src/github.com/matrix-org/dendrite/common/sql.go
index f3de66f11..7ac9ac140 100644
--- a/src/github.com/matrix-org/dendrite/common/sql.go
+++ b/src/github.com/matrix-org/dendrite/common/sql.go
@@ -16,6 +16,8 @@ package common
 
 import (
 	"database/sql"
+
+	"github.com/lib/pq"
 )
 
 // A Transaction is something that can be committed or rolledback.
@@ -66,3 +68,9 @@ func TxStmt(transaction *sql.Tx, statement *sql.Stmt) *sql.Stmt {
 	}
 	return statement
 }
+
+// IsUniqueConstraintViolationErr returns true if the error is a postgresql unique_violation error
+func IsUniqueConstraintViolationErr(err error) bool {
+	pqErr, ok := err.(*pq.Error)
+	return ok && pqErr.Code == "23505"
+}