SQL providers: make sure we don't exceed the allowed placeholders

Fixes #1415

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/dataprovider/sqlcommon.go

@@ -958,63 +958,86 @@ func sqlCommonGetUsersInGroups(names []string, dbHandle sqlQuerier) ([]string, e
 	if len(names) == 0 {
 		return nil, nil
 	}
+	maxNames := len(sqlPlaceholders)
+	usernames := make([]string, 0, len(names))
+
 	ctx, cancel := context.WithTimeout(context.Background(), defaultSQLQueryTimeout)
 	defer cancel()
 
-	q := getUsersInGroupsQuery(len(names))
-	args := make([]any, 0, len(names))
-	for _, name := range names {
-		args = append(args, name)
-	}
+	for len(names) > 0 {
+		if maxNames > len(names) {
+			maxNames = len(names)
+		}
 
-	usernames := make([]string, 0, len(names))
-	rows, err := dbHandle.QueryContext(ctx, q, args...)
-	if err != nil {
-		return nil, err
-	}
-	defer rows.Close()
+		q := getUsersInGroupsQuery(maxNames)
+		args := make([]any, 0, maxNames)
+		for _, name := range names[:maxNames] {
+			args = append(args, name)
+		}
 
-	for rows.Next() {
-		var username string
-		err = rows.Scan(&username)
+		rows, err := dbHandle.QueryContext(ctx, q, args...)
+		if err != nil {
+			return nil, err
+		}
+		defer rows.Close()
+
+		for rows.Next() {
+			var username string
+			err = rows.Scan(&username)
+			if err != nil {
+				return usernames, err
+			}
+			usernames = append(usernames, username)
+		}
+		err = rows.Err()
 		if err != nil {
 			return usernames, err
 		}
-		usernames = append(usernames, username)
+		names = names[maxNames:]
 	}
-	return usernames, rows.Err()
+	return usernames, nil
 }
 
 func sqlCommonGetGroupsWithNames(names []string, dbHandle sqlQuerier) ([]Group, error) {
 	if len(names) == 0 {
 		return nil, nil
 	}
-	ctx, cancel := context.WithTimeout(context.Background(), defaultSQLQueryTimeout)
-	defer cancel()
-
-	q := getGroupsWithNamesQuery(len(names))
-	args := make([]any, 0, len(names))
-	for _, name := range names {
-		args = append(args, name)
-	}
+	maxNames := len(sqlPlaceholders)
 	groups := make([]Group, 0, len(names))
-	rows, err := dbHandle.QueryContext(ctx, q, args...)
-	if err != nil {
-		return groups, err
-	}
-	defer rows.Close()
+	for len(names) > 0 {
+		if maxNames > len(names) {
+			maxNames = len(names)
+		}
+		ctx, cancel := context.WithTimeout(context.Background(), defaultSQLQueryTimeout)
+		defer cancel()
 
-	for rows.Next() {
-		group, err := getGroupFromDbRow(rows)
+		q := getGroupsWithNamesQuery(maxNames)
+		args := make([]any, 0, maxNames)
+		for _, name := range names[:maxNames] {
+			args = append(args, name)
+		}
+		rows, err := dbHandle.QueryContext(ctx, q, args...)
 		if err != nil {
 			return groups, err
 		}
-		groups = append(groups, group)
-	}
-	err = rows.Err()
-	if err != nil {
-		return groups, err
+		defer rows.Close()
+
+		for rows.Next() {
+			group, err := getGroupFromDbRow(rows)
+			if err != nil {
+				return groups, err
+			}
+			groups = append(groups, group)
+		}
+		err = rows.Err()
+		if err != nil {
+			return groups, err
+		}
+		names = names[maxNames:]
 	}
+	ctx, cancel := context.WithTimeout(context.Background(), defaultSQLQueryTimeout)
+	defer cancel()
+
 	return getGroupsWithVirtualFolders(ctx, groups, dbHandle)
 }
 
@@ -1535,6 +1558,9 @@ func sqlCommonGetRecentlyUpdatedUsers(after int64, dbHandle sqlQuerier) ([]User,
 		}
 	}
 	groupNames = util.RemoveDuplicates(groupNames, false)
+	if len(groupNames) == 0 {
+		return users, nil
+	}
 	groups, err := sqlCommonGetGroupsWithNames(groupNames, dbHandle)
 	if err != nil {
 		return users, err
@@ -1553,15 +1579,23 @@ func sqlCommonGetRecentlyUpdatedUsers(after int64, dbHandle sqlQuerier) ([]User,
 	return users, nil
 }
 
+func sqlGetMaxUsersForQuotaCheckRange() int {
+	maxUsers := 50
+	if maxUsers > len(sqlPlaceholders) {
+		maxUsers = len(sqlPlaceholders)
+	}
+	return maxUsers
+}
+
 func sqlCommonGetUsersForQuotaCheck(toFetch map[string]bool, dbHandle sqlQuerier) ([]User, error) {
-	users := make([]User, 0, 30)
+	maxUsers := sqlGetMaxUsersForQuotaCheckRange()
+	users := make([]User, 0, maxUsers)
 
 	usernames := make([]string, 0, len(toFetch))
 	for k := range toFetch {
 		usernames = append(usernames, k)
 	}
 
-	maxUsers := 30
 	for len(usernames) > 0 {
 		if maxUsers > len(usernames) {
 			maxUsers = len(usernames)