qerror: qerror_format(): return an allocated string

Simplifies current and future users.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>

error.c

@@ -65,10 +65,7 @@ bool error_is_set(Error **errp)
 const char *error_get_pretty(Error *err)
 {
     if (err->msg == NULL) {
-        QString *str;
-        str = qerror_format(err->fmt, err->obj);
-        err->msg = g_strdup(qstring_get_str(str));
-        QDECREF(str);
+        err->msg = qerror_format(err->fmt, err->obj);
     }
 
     return err->msg;

qerror.c

@@ -493,9 +493,11 @@ static QString *qerror_format_desc(QDict *error,
     return qstring;
 }
 
-QString *qerror_format(const char *fmt, QDict *error)
+char *qerror_format(const char *fmt, QDict *error)
 {
     const QErrorStringTable *entry = NULL;
+    QString *qstr;
+    char *ret;
     int i;
 
     for (i = 0; qerror_table[i].error_fmt; i++) {
@@ -505,7 +507,11 @@ QString *qerror_format(const char *fmt, QDict *error)
         }
     }
 
-    return qerror_format_desc(error, entry);
+    qstr = qerror_format_desc(error, entry);
+    ret = g_strdup(qstring_get_str(qstr));
+    QDECREF(qstr);
+
+    return ret;
 }
 
 /**

qerror.h

@@ -34,7 +34,7 @@ QString *qerror_human(const QError *qerror);
 void qerror_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
 void qerror_report_err(Error *err);
 void assert_no_error(Error *err);
-QString *qerror_format(const char *fmt, QDict *error);
+char *qerror_format(const char *fmt, QDict *error);
 
 /*
  * QError class list