+ case 'u': {
+ /* C++11 style 16bit unicode */
+
+ int a[4];
+ unsigned i;
+ uint32_t c;
+
+ if (length != (size_t) -1 && length < 5)
+ return -EINVAL;
+
+ for (i = 0; i < 4; i++) {
+ a[i] = unhexchar(p[1 + i]);
+ if (a[i] < 0)
+ return a[i];
+ }
+
+ c = ((uint32_t) a[0] << 12U) | ((uint32_t) a[1] << 8U) | ((uint32_t) a[2] << 4U) | (uint32_t) a[3];
+
+ /* Don't allow 0 chars */
+ if (c == 0)
+ return -EINVAL;
+
+ if (c < 128)
+ *ret = c;
+ else {
+ if (!ret_unicode)
+ return -EINVAL;
+
+ *ret = 0;
+ *ret_unicode = c;
+ }
+
+ r = 5;
+ break;
+ }
+
+ case 'U': {
+ /* C++11 style 32bit unicode */
+
+ int a[8];
+ unsigned i;
+ uint32_t c;
+
+ if (length != (size_t) -1 && length < 9)
+ return -EINVAL;
+
+ for (i = 0; i < 8; i++) {
+ a[i] = unhexchar(p[1 + i]);
+ if (a[i] < 0)
+ return a[i];
+ }
+
+ c = ((uint32_t) a[0] << 28U) | ((uint32_t) a[1] << 24U) | ((uint32_t) a[2] << 20U) | ((uint32_t) a[3] << 16U) |
+ ((uint32_t) a[4] << 12U) | ((uint32_t) a[5] << 8U) | ((uint32_t) a[6] << 4U) | (uint32_t) a[7];
+
+ /* Don't allow 0 chars */
+ if (c == 0)
+ return -EINVAL;
+
+ /* Don't allow invalid code points */
+ if (!unichar_is_valid(c))
+ return -EINVAL;
+
+ if (c < 128)
+ *ret = c;
+ else {
+ if (!ret_unicode)
+ return -EINVAL;
+
+ *ret = 0;
+ *ret_unicode = c;
+ }
+
+ r = 9;
+ break;
+ }
+