fix: pgbouncer

#759

Author: exfly

conn.go

@@ -833,6 +833,7 @@ func decideColumnFormats(colTyps []fieldDesc, forceText bool) (colFmts []format,
 }
 
 func (cn *conn) prepareTo(q, stmtName string) *stmt {
+	var err error
 	st := &stmt{cn: cn, name: stmtName}
 
 	b := cn.writeBuf('P')
@@ -844,13 +845,29 @@ func (cn *conn) prepareTo(q, stmtName string) *stmt {
 	b.byte('S')
 	b.string(st.name)
 
-	b.next('S')
+	if stmtName != "" {
+		b.next('S') // sync
+	} else {
+		b.next('H') // flush
+	}
 	cn.send(b)
 
-	cn.readParseResponse()
-	st.paramTyps, st.colNames, st.colTyps = cn.readStatementDescribeResponse()
+	if err := cn.readParseResponse(); err != nil {
+		cn.send(cn.writeBuf('S')) // sync
+		cn.readReadyForQuery()
+		panic(err)
+	}
+
+	st.paramTyps, st.colNames, st.colTyps, err = cn.readStatementDescribeResponse()
+	if err != nil {
+		cn.send(cn.writeBuf('S')) // sync
+		cn.readReadyForQuery()
+		panic(err)
+	}
 	st.colFmts, st.colFmtData = decideColumnFormats(st.colTyps, cn.disablePreparedBinaryResult)
-	cn.readReadyForQuery()
+	if stmtName != "" {
+		cn.readReadyForQuery()
+	}
 	return st
 }
 
@@ -911,7 +928,11 @@ func (cn *conn) query(query string, args []driver.Value) (_ *rows, err error) {
 	if cn.binaryParameters {
 		cn.sendBinaryModeQuery(query, args)
 
-		cn.readParseResponse()
+		if err := cn.readParseResponse(); err != nil {
+			cn.readReadyForQuery()
+			panic(err)
+		}
+
 		cn.readBindResponse()
 		rows := &rows{cn: cn}
 		rows.rowsHeader = cn.readPortalDescribeResponse()
@@ -944,7 +965,10 @@ func (cn *conn) Exec(query string, args []driver.Value) (res driver.Result, err
 	if cn.binaryParameters {
 		cn.sendBinaryModeQuery(query, args)
 
-		cn.readParseResponse()
+		if err := cn.readParseResponse(); err != nil {
+			cn.readReadyForQuery()
+			panic(err)
+		}
 		cn.readBindResponse()
 		cn.readPortalDescribeResponse()
 		cn.postExecuteWorkaround()
@@ -1824,25 +1848,25 @@ func (cn *conn) processBackendKeyData(r *readBuf) {
 	cn.secretKey = r.int32()
 }
 
-func (cn *conn) readParseResponse() {
+func (cn *conn) readParseResponse() (err error) {
 	t, r := cn.recv1()
 	switch t {
 	case '1':
-		return
 	case 'E':
-		err := parseError(r)
-		cn.readReadyForQuery()
-		panic(err)
+		err = parseError(r)
 	default:
 		cn.err.set(driver.ErrBadConn)
-		errorf("unexpected Parse response %q", t)
+		err = fmterrorf("unexpected Parse response %q", t)
 	}
+
+	return
 }
 
 func (cn *conn) readStatementDescribeResponse() (
 	paramTyps []oid.Oid,
 	colNames []string,
 	colTyps []fieldDesc,
+	err error,
 ) {
 	for {
 		t, r := cn.recv1()
@@ -1854,17 +1878,17 @@ func (cn *conn) readStatementDescribeResponse() (
 				paramTyps[i] = r.oid()
 			}
 		case 'n':
-			return paramTyps, nil, nil
+			return
 		case 'T':
 			colNames, colTyps = parseStatementRowDescribe(r)
-			return paramTyps, colNames, colTyps
+			return
 		case 'E':
-			err := parseError(r)
-			cn.readReadyForQuery()
-			panic(err)
+			err = parseError(r)
+			return
 		default:
 			cn.err.set(driver.ErrBadConn)
-			errorf("unexpected Describe statement response %q", t)
+			err = fmterrorf("unexpected Describe statement response %q", t)
+			return
 		}
 	}
 }