qstring: Make conversion from QObject * accept null

qobject_to_qstring() crashes on null, which is a trap for the unwary.
Return null instead, and simplify a few callers.

Backports commit 7f0278435df1fa845b3bd9556942f89296d4246b from qemu
This commit is contained in:
Markus Armbruster 2018-02-17 14:23:15 -05:00 committed by Lioncash
parent d25b8420d0
commit b9cf91307e
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GPG Key ID: 4E3C3CC1031BA9C7
3 changed files with 8 additions and 13 deletions

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@ -255,15 +255,15 @@ static void qmp_input_type_str(Visitor *v, char **obj, const char *name,
Error **errp) Error **errp)
{ {
QmpInputVisitor *qiv = to_qiv(v); QmpInputVisitor *qiv = to_qiv(v);
QObject *qobj = qmp_input_get_object(qiv, name, true); QString *qstr = qobject_to_qstring(qmp_input_get_object(qiv, name, true));
if (!qobj || qobject_type(qobj) != QTYPE_QSTRING) { if (!qstr) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null", error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"string"); "string");
return; return;
} }
*obj = g_strdup(qstring_get_str(qobject_to_qstring(qobj))); *obj = g_strdup(qstring_get_str(qstr));
} }
static void qmp_input_type_number(Visitor *v, double *obj, const char *name, static void qmp_input_type_number(Visitor *v, double *obj, const char *name,

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@ -282,8 +282,7 @@ QDict *qdict_get_qdict(const QDict *qdict, const char *key)
*/ */
const char *qdict_get_str(const QDict *qdict, const char *key) const char *qdict_get_str(const QDict *qdict, const char *key)
{ {
QObject *obj = qdict_get_obj(qdict, key, QTYPE_QSTRING); return qstring_get_str(qobject_to_qstring(qdict_get(qdict, key)));
return qstring_get_str(qobject_to_qstring(obj));
} }
/** /**
@ -325,13 +324,9 @@ bool qdict_get_try_bool(const QDict *qdict, const char *key, int def_value)
*/ */
const char *qdict_get_try_str(const QDict *qdict, const char *key) const char *qdict_get_try_str(const QDict *qdict, const char *key)
{ {
QObject *obj; QString *qstr = qobject_to_qstring(qdict_get(qdict, key));
obj = qdict_get(qdict, key); return qstr ? qstring_get_str(qstr) : NULL;
if (!obj || qobject_type(obj) != QTYPE_QSTRING)
return NULL;
return qstring_get_str(qobject_to_qstring(obj));
} }
/** /**

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@ -117,9 +117,9 @@ void qstring_append_chr(QString *qstring, int c)
*/ */
QString *qobject_to_qstring(const QObject *obj) QString *qobject_to_qstring(const QObject *obj)
{ {
if (qobject_type(obj) != QTYPE_QSTRING) if (!obj || qobject_type(obj) != QTYPE_QSTRING) {
return NULL; return NULL;
}
return container_of(obj, QString, base); return container_of(obj, QString, base);
} }