qapi: Fix string-input-visitor to reject NaN and infinities

The string-input-visitor happily accepts NaN and infinities when parsing
numbers (doubles). They shouldn't. Fix that.

Also, add two test cases, testing if "NaN" and "inf" is properly
rejected.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181121164421.20780-4-david@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/string-input-visitor.c

@@ -20,6 +20,7 @@
 #include "qemu/option.h"
 #include "qemu/queue.h"
 #include "qemu/range.h"
+#include "qemu/cutils.h"
 
 
 struct StringInputVisitor
@@ -313,12 +314,9 @@ static void parse_type_number(Visitor *v, const char *name, double *obj,
                               Error **errp)
 {
     StringInputVisitor *siv = to_siv(v);
-    char *endp = (char *) siv->string;
     double val;
 
-    errno = 0;
-    val = strtod(siv->string, &endp);
-    if (errno || endp == siv->string || *endp) {
+    if (qemu_strtod_finite(siv->string, NULL, &val)) {
         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
                    "number");
         return;

tests/test-string-input-visitor.c

@@ -252,6 +252,19 @@ static void test_visitor_in_number(TestInputVisitorData *data,
     visit_type_number(v, NULL, &res, &err);
     g_assert(!err);
     g_assert_cmpfloat(res, ==, value);
+
+    /* NaN and infinity has to be rejected */
+
+    v = visitor_input_test_init(data, "NaN");
+
+    visit_type_number(v, NULL, &res, &err);
+    error_free_or_abort(&err);
+
+    v = visitor_input_test_init(data, "inf");
+
+    visit_type_number(v, NULL, &res, &err);
+    error_free_or_abort(&err);
+
 }
 
 static void test_visitor_in_string(TestInputVisitorData *data,