diff --git a/tests/check-qjson.c b/tests/check-qjson.c
index 32ffb436df..ec85a0cf2d 100644
--- a/tests/check-qjson.c
+++ b/tests/check-qjson.c
@@ -1,8 +1,10 @@
 /*
  * Copyright IBM, Corp. 2009
+ * Copyright (c) 2013 Red Hat Inc.
  *
  * Authors:
  *  Anthony Liguori   <aliguori@us.ibm.com>
+ *  Markus Armbruster <armbru@redhat.com>,
  *
  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
  * See the COPYING.LIB file in the top-level directory.
@@ -131,6 +133,667 @@ static void single_quote_string(void)
     }
 }
 
+static void utf8_string(void)
+{
+    /*
+     * FIXME Current behavior for invalid UTF-8 sequences is
+     * incorrect.  This test expects current, incorrect results.
+     * They're all marked "bug:" below, and are to be replaced by
+     * correct ones as the bugs get fixed.
+     *
+     * The JSON parser rejects some invalid sequences, but accepts
+     * others without correcting the problem.
+     *
+     * The JSON formatter replaces some invalid sequences by U+FFFF (a
+     * noncharacter), and goes wonky for others.
+     *
+     * For both directions, we should either reject all invalid
+     * sequences, or minimize overlong sequences and replace all other
+     * invalid sequences by a suitable replacement character.  A
+     * common choice for replacement is U+FFFD.
+     *
+     * Problem: we can't easily deal with embedded U+0000.  Parsing
+     * the JSON string "this \\u0000" is fun" yields "this \0 is fun",
+     * which gets misinterpreted as NUL-terminated "this ".  We should
+     * consider using overlong encoding \xC0\x80 for U+0000 ("modified
+     * UTF-8").
+     *
+     * Test cases are scraped from Markus Kuhn's UTF-8 decoder
+     * capability and stress test at
+     * http://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt
+     */
+    static const struct {
+        const char *json_in;
+        const char *utf8_out;
+        const char *json_out;   /* defaults to @json_in */
+        const char *utf8_in;    /* defaults to @utf8_out */
+    } test_cases[] = {
+        /*
+         * Bug markers used here:
+         * - bug: not corrected
+         *   JSON parser fails to correct invalid sequence(s)
+         * - bug: rejected
+         *   JSON parser rejects invalid sequence(s)
+         *   We may choose to define this as feature
+         * - bug: want "\"...\""
+         *   JSON formatter produces incorrect result, this is the
+         *   correct one, assuming replacement character U+FFFF
+         * - bug: want "..." (no \")
+         *   JSON parser produces incorrect result, this is the
+         *   correct one, assuming replacement character U+FFFF
+         *   We may choose to reject instead of replace
+         * Not marked explicitly, but trivial to find:
+         * - JSON formatter replacing invalid sequence by \\uFFFF is a
+         *   bug if we want it to fail for invalid sequences.
+         */
+
+        /* 1  Some correct UTF-8 text */
+        {
+            /* a bit of German */
+            "\"Falsches \xC3\x9C" "ben von Xylophonmusik qu\xC3\xA4lt"
+            " jeden gr\xC3\xB6\xC3\x9F" "eren Zwerg.\"",
+            "Falsches \xC3\x9C" "ben von Xylophonmusik qu\xC3\xA4lt"
+            " jeden gr\xC3\xB6\xC3\x9F" "eren Zwerg.",
+            "\"Falsches \\u00DCben von Xylophonmusik qu\\u00E4lt"
+            " jeden gr\\u00F6\\u00DFeren Zwerg.\"",
+        },
+        {
+            /* a bit of Greek */
+            "\"\xCE\xBA\xE1\xBD\xB9\xCF\x83\xCE\xBC\xCE\xB5\"",
+            "\xCE\xBA\xE1\xBD\xB9\xCF\x83\xCE\xBC\xCE\xB5",
+            "\"\\u03BA\\u1F79\\u03C3\\u03BC\\u03B5\"",
+        },
+        /* 2  Boundary condition test cases */
+        /* 2.1  First possible sequence of a certain length */
+        /* 2.1.1  1 byte U+0000 */
+        {
+            "\"\\u0000\"",
+            "",                 /* bug: want overlong "\xC0\x80" */
+            "\"\"",             /* bug: want "\"\\u0000\"" */
+        },
+        /* 2.1.2  2 bytes U+0080 */
+        {
+            "\"\xC2\x80\"",
+            "\xC2\x80",
+            "\"\\u0080\"",
+        },
+        /* 2.1.3  3 bytes U+0800 */
+        {
+            "\"\xE0\xA0\x80\"",
+            "\xE0\xA0\x80",
+            "\"\\u0800\"",
+        },
+        /* 2.1.4  4 bytes U+10000 */
+        {
+            "\"\xF0\x90\x80\x80\"",
+            "\xF0\x90\x80\x80",
+            "\"\\u0400\\uFFFF\"", /* bug: want "\"\\uD800\\uDC00\"" */
+        },
+        /* 2.1.5  5 bytes U+200000 */
+        {
+            "\"\xF8\x88\x80\x80\x80\"",
+            NULL,                        /* bug: rejected */
+            "\"\\u8200\\uFFFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+            "\xF8\x88\x80\x80\x80",
+        },
+        /* 2.1.6  6 bytes U+4000000 */
+        {
+            "\"\xFC\x84\x80\x80\x80\x80\"",
+            NULL,                               /* bug: rejected */
+            "\"\\uC100\\uFFFF\\uFFFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+            "\xFC\x84\x80\x80\x80\x80",
+        },
+        /* 2.2  Last possible sequence of a certain length */
+        /* 2.2.1  1 byte U+007F */
+        {
+            "\"\x7F\"",
+            "\x7F",
+            "\"\177\"",
+        },
+        /* 2.2.2  2 bytes U+07FF */
+        {
+            "\"\xDF\xBF\"",
+            "\xDF\xBF",
+            "\"\\u07FF\"",
+        },
+        /* 2.2.3  3 bytes U+FFFF */
+        {
+            "\"\xEF\xBF\xBF\"",
+            "\xEF\xBF\xBF",
+            "\"\\uFFFF\"",
+        },
+        /* 2.2.4  4 bytes U+1FFFFF */
+        {
+            "\"\xF7\xBF\xBF\xBF\"",
+            NULL,                 /* bug: rejected */
+            "\"\\u7FFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+            "\xF7\xBF\xBF\xBF",
+        },
+        /* 2.2.5  5 bytes U+3FFFFFF */
+        {
+            "\"\xFB\xBF\xBF\xBF\xBF\"",
+            NULL,                        /* bug: rejected */
+            "\"\\uBFFF\\uFFFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+            "\xFB\xBF\xBF\xBF\xBF",
+        },
+        /* 2.2.6  6 bytes U+7FFFFFFF */
+        {
+            "\"\xFD\xBF\xBF\xBF\xBF\xBF\"",
+            NULL,                               /* bug: rejected */
+            "\"\\uDFFF\\uFFFF\\uFFFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+            "\xFD\xBF\xBF\xBF\xBF\xBF",
+        },
+        /* 2.3  Other boundary conditions */
+        {
+            /* U+D7FF */
+            "\"\xED\x9F\xBF\"",
+            "\xED\x9F\xBF",
+            "\"\\uD7FF\"",
+        },
+        {
+            /* U+E000 */
+            "\"\xEE\x80\x80\"",
+            "\xEE\x80\x80",
+            "\"\\uE000\"",
+        },
+        {
+            /* U+FFFD */
+            "\"\xEF\xBF\xBD\"",
+            "\xEF\xBF\xBD",
+            "\"\\uFFFD\"",
+        },
+        {
+            /* U+10FFFF */
+            "\"\xF4\x8F\xBF\xBF\"",
+            "\xF4\x8F\xBF\xBF",
+            "\"\\u43FF\\uFFFF\"", /* bug: want "\"\\uDBFF\\uDFFF\"" */
+        },
+        {
+            /* U+110000 */
+            "\"\xF4\x90\x80\x80\"",
+            "\xF4\x90\x80\x80",
+            "\"\\u4400\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+        },
+        /* 3  Malformed sequences */
+        /* 3.1  Unexpected continuation bytes */
+        /* 3.1.1  First continuation byte */
+        {
+            "\"\x80\"",
+            "\x80",             /* bug: not corrected */
+            "\"\\uFFFF\"",
+        },
+        /* 3.1.2  Last continuation byte */
+        {
+            "\"\xBF\"",
+            "\xBF",             /* bug: not corrected */
+            "\"\\uFFFF\"",
+        },
+        /* 3.1.3  2 continuation bytes */
+        {
+            "\"\x80\xBF\"",
+            "\x80\xBF",         /* bug: not corrected */
+            "\"\\uFFFF\\uFFFF\"",
+        },
+        /* 3.1.4  3 continuation bytes */
+        {
+            "\"\x80\xBF\x80\"",
+            "\x80\xBF\x80",     /* bug: not corrected */
+            "\"\\uFFFF\\uFFFF\\uFFFF\"",
+        },
+        /* 3.1.5  4 continuation bytes */
+        {
+            "\"\x80\xBF\x80\xBF\"",
+            "\x80\xBF\x80\xBF", /* bug: not corrected */
+            "\"\\uFFFF\\uFFFF\\uFFFF\\uFFFF\"",
+        },
+        /* 3.1.6  5 continuation bytes */
+        {
+            "\"\x80\xBF\x80\xBF\x80\"",
+            "\x80\xBF\x80\xBF\x80", /* bug: not corrected */
+            "\"\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\"",
+        },
+        /* 3.1.7  6 continuation bytes */
+        {
+            "\"\x80\xBF\x80\xBF\x80\xBF\"",
+            "\x80\xBF\x80\xBF\x80\xBF", /* bug: not corrected */
+            "\"\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\"",
+        },
+        /* 3.1.8  7 continuation bytes */
+        {
+            "\"\x80\xBF\x80\xBF\x80\xBF\x80\"",
+            "\x80\xBF\x80\xBF\x80\xBF\x80", /* bug: not corrected */
+            "\"\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\"",
+        },
+        /* 3.1.9  Sequence of all 64 possible continuation bytes */
+        {
+            "\"\x80\x81\x82\x83\x84\x85\x86\x87"
+            "\x88\x89\x8A\x8B\x8C\x8D\x8E\x8F"
+            "\x90\x91\x92\x93\x94\x95\x96\x97"
+            "\x98\x99\x9A\x9B\x9C\x9D\x9E\x9F"
+            "\xA0\xA1\xA2\xA3\xA4\xA5\xA6\xA7"
+            "\xA8\xA9\xAA\xAB\xAC\xAD\xAE\xAF"
+            "\xB0\xB1\xB2\xB3\xB4\xB5\xB6\xB7"
+            "\xB8\xB9\xBA\xBB\xBC\xBD\xBE\xBF\"",
+             /* bug: not corrected */
+            "\x80\x81\x82\x83\x84\x85\x86\x87"
+            "\x88\x89\x8A\x8B\x8C\x8D\x8E\x8F"
+            "\x90\x91\x92\x93\x94\x95\x96\x97"
+            "\x98\x99\x9A\x9B\x9C\x9D\x9E\x9F"
+            "\xA0\xA1\xA2\xA3\xA4\xA5\xA6\xA7"
+            "\xA8\xA9\xAA\xAB\xAC\xAD\xAE\xAF"
+            "\xB0\xB1\xB2\xB3\xB4\xB5\xB6\xB7"
+            "\xB8\xB9\xBA\xBB\xBC\xBD\xBE\xBF",
+            "\"\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF"
+            "\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF"
+            "\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF"
+            "\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF"
+            "\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF"
+            "\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF"
+            "\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF"
+            "\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\""
+        },
+        /* 3.2  Lonely start characters */
+        /* 3.2.1  All 32 first bytes of 2-byte sequences, followed by space */
+        {
+            "\"\xC0 \xC1 \xC2 \xC3 \xC4 \xC5 \xC6 \xC7 "
+            "\xC8 \xC9 \xCA \xCB \xCC \xCD \xCE \xCF "
+            "\xD0 \xD1 \xD2 \xD3 \xD4 \xD5 \xD6 \xD7 "
+            "\xD8 \xD9 \xDA \xDB \xDC \xDD \xDE \xDF \"",
+            NULL,               /* bug: rejected */
+            "\"\\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF "
+            "\\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF "
+            "\\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF "
+            "\\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \"",
+            "\xC0 \xC1 \xC2 \xC3 \xC4 \xC5 \xC6 \xC7 "
+            "\xC8 \xC9 \xCA \xCB \xCC \xCD \xCE \xCF "
+            "\xD0 \xD1 \xD2 \xD3 \xD4 \xD5 \xD6 \xD7 "
+            "\xD8 \xD9 \xDA \xDB \xDC \xDD \xDE \xDF ",
+        },
+        /* 3.2.2  All 16 first bytes of 3-byte sequences, followed by space */
+        {
+            "\"\xE0 \xE1 \xE2 \xE3 \xE4 \xE5 \xE6 \xE7 "
+            "\xE8 \xE9 \xEA \xEB \xEC \xED \xEE \xEF \"",
+            /* bug: not corrected */
+            "\xE0 \xE1 \xE2 \xE3 \xE4 \xE5 \xE6 \xE7 "
+            "\xE8 \xE9 \xEA \xEB \xEC \xED \xEE \xEF ",
+            "\"\\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF "
+            "\\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \"",
+        },
+        /* 3.2.3  All 8 first bytes of 4-byte sequences, followed by space */
+        {
+            "\"\xF0 \xF1 \xF2 \xF3 \xF4 \xF5 \xF6 \xF7 \"",
+            NULL,               /* bug: rejected */
+            "\"\\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \\uFFFF \"",
+            "\xF0 \xF1 \xF2 \xF3 \xF4 \xF5 \xF6 \xF7 ",
+        },
+        /* 3.2.4  All 4 first bytes of 5-byte sequences, followed by space */
+        {
+            "\"\xF8 \xF9 \xFA \xFB \"",
+            NULL,               /* bug: rejected */
+            "\"\\uFFFF \\uFFFF \\uFFFF \\uFFFF \"",
+            "\xF8 \xF9 \xFA \xFB ",
+        },
+        /* 3.2.5  All 2 first bytes of 6-byte sequences, followed by space */
+        {
+            "\"\xFC \xFD \"",
+            NULL,               /* bug: rejected */
+            "\"\\uFFFF \\uFFFF \"",
+            "\xFC \xFD ",
+        },
+        /* 3.3  Sequences with last continuation byte missing */
+        /* 3.3.1  2-byte sequence with last byte missing (U+0000) */
+        {
+            "\"\xC0\"",
+            NULL,               /* bug: rejected */
+            "\"\\uFFFF\"",
+            "\xC0",
+        },
+        /* 3.3.2  3-byte sequence with last byte missing (U+0000) */
+        {
+            "\"\xE0\x80\"",
+            "\xE0\x80",           /* bug: not corrected */
+            "\"\\uFFFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+        },
+        /* 3.3.3  4-byte sequence with last byte missing (U+0000) */
+        {
+            "\"\xF0\x80\x80\"",
+            "\xF0\x80\x80",     /* bug: not corrected */
+            "\"\\u0000\"",      /* bug: want "\"\\uFFFF\"" */
+        },
+        /* 3.3.4  5-byte sequence with last byte missing (U+0000) */
+        {
+            /* invalid */
+            "\"\xF8\x80\x80\x80\"", /* bug: not corrected */
+            NULL,                   /* bug: rejected */
+            "\"\\u8000\\uFFFF\"",   /* bug: want "\"\\uFFFF\"" */
+            "\xF8\x80\x80\x80",
+        },
+        /* 3.3.5  6-byte sequence with last byte missing (U+0000) */
+        {
+            "\"\xFC\x80\x80\x80\x80\"",
+            NULL,                        /* bug: rejected */
+            "\"\\uC000\\uFFFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+            "\xFC\x80\x80\x80\x80",
+        },
+        /* 3.3.6  2-byte sequence with last byte missing (U+07FF) */
+        {
+            "\"\xDF\"",
+            "\xDF",             /* bug: not corrected */
+            "\"\\uFFFF\"",
+        },
+        /* 3.3.7  3-byte sequence with last byte missing (U+FFFF) */
+        {
+            "\"\xEF\xBF\"",
+            "\xEF\xBF",           /* bug: not corrected */
+            "\"\\uFFFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+        },
+        /* 3.3.8  4-byte sequence with last byte missing (U+1FFFFF) */
+        {
+            "\"\xF7\xBF\xBF\"",
+            NULL,               /* bug: rejected */
+            "\"\\u7FFF\"",      /* bug: want "\"\\uFFFF\"" */
+            "\xF7\xBF\xBF",
+        },
+        /* 3.3.9  5-byte sequence with last byte missing (U+3FFFFFF) */
+        {
+            "\"\xFB\xBF\xBF\xBF\"",
+            NULL,                 /* bug: rejected */
+            "\"\\uBFFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+            "\xFB\xBF\xBF\xBF",
+        },
+        /* 3.3.10  6-byte sequence with last byte missing (U+7FFFFFFF) */
+        {
+            "\"\xFD\xBF\xBF\xBF\xBF\"",
+            NULL,                        /* bug: rejected */
+            "\"\\uDFFF\\uFFFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"", */
+            "\xFD\xBF\xBF\xBF\xBF",
+        },
+        /* 3.4  Concatenation of incomplete sequences */
+        {
+            "\"\xC0\xE0\x80\xF0\x80\x80\xF8\x80\x80\x80\xFC\x80\x80\x80\x80"
+            "\xDF\xEF\xBF\xF7\xBF\xBF\xFB\xBF\xBF\xBF\xFD\xBF\xBF\xBF\xBF\"",
+            NULL,               /* bug: rejected */
+            /* bug: want "\"\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF"
+               "\\uFFFF\\uFFFF\\uFFFF\\uFFFF\\uFFFF\"" */
+            "\"\\u0020\\uFFFF\\u0000\\u8000\\uFFFF\\uC000\\uFFFF\\uFFFF"
+            "\\u07EF\\uFFFF\\u7FFF\\uBFFF\\uFFFF\\uDFFF\\uFFFF\\uFFFF\"",
+            "\xC0\xE0\x80\xF0\x80\x80\xF8\x80\x80\x80\xFC\x80\x80\x80\x80"
+            "\xDF\xEF\xBF\xF7\xBF\xBF\xFB\xBF\xBF\xBF\xFD\xBF\xBF\xBF\xBF",
+        },
+        /* 3.5  Impossible bytes */
+        {
+            "\"\xFE\"",
+            NULL,               /* bug: rejected */
+            "\"\\uFFFF\"",
+            "\xFE",
+        },
+        {
+            "\"\xFF\"",
+            NULL,               /* bug: rejected */
+            "\"\\uFFFF\"",
+            "\xFF",
+        },
+        {
+            "\"\xFE\xFE\xFF\xFF\"",
+            NULL,                 /* bug: rejected */
+            /* bug: want "\"\\uFFFF\\uFFFF\\uFFFF\\uFFFF\"" */
+            "\"\\uEFBF\\uFFFF\"",
+            "\xFE\xFE\xFF\xFF",
+        },
+        /* 4  Overlong sequences */
+        /* 4.1  Overlong '/' */
+        {
+            "\"\xC0\xAF\"",
+            NULL,               /* bug: rejected */
+            "\"\\u002F\"",      /* bug: want "\"/\"" */
+            "\xC0\xAF",
+        },
+        {
+            "\"\xE0\x80\xAF\"",
+            "\xE0\x80\xAF",     /* bug: not corrected */
+            "\"\\u002F\"",      /* bug: want "\"/\"" */
+        },
+        {
+            "\"\xF0\x80\x80\xAF\"",
+            "\xF0\x80\x80\xAF",  /* bug: not corrected */
+            "\"\\u0000\\uFFFF\"" /* bug: want "\"/\"" */
+        },
+        {
+            "\"\xF8\x80\x80\x80\xAF\"",
+            NULL,                        /* bug: rejected */
+            "\"\\u8000\\uFFFF\\uFFFF\"", /* bug: want "\"/\"" */
+            "\xF8\x80\x80\x80\xAF",
+        },
+        {
+            "\"\xFC\x80\x80\x80\x80\xAF\"",
+            NULL,                               /* bug: rejected */
+            "\"\\uC000\\uFFFF\\uFFFF\\uFFFF\"", /* bug: want "\"/\"" */
+            "\xFC\x80\x80\x80\x80\xAF",
+        },
+        /* 4.2  Maximum overlong sequences */
+        {
+            /* \U+007F */
+            "\"\xC1\xBF\"",
+            NULL,               /* bug: rejected */
+            "\"\\u007F\"",      /* bug: want "\"\177\"" */
+            "\xC1\xBF",
+        },
+        {
+            /* \U+07FF */
+            "\"\xE0\x9F\xBF\"",
+            "\xE0\x9F\xBF",     /* bug: not corrected */
+            "\"\\u07FF\"",
+        },
+        {
+            /* \U+FFFF */
+            "\"\xF0\x8F\xBF\xBF\"",
+            "\xF0\x8F\xBF\xBF",   /* bug: not corrected */
+            "\"\\u03FF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+        },
+        {
+            /* \U+1FFFFF */
+            "\"\xF8\x87\xBF\xBF\xBF\"",
+            NULL,                        /* bug: rejected */
+            "\"\\u81FF\\uFFFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+            "\xF8\x87\xBF\xBF\xBF",
+        },
+        {
+            /* \U+3FFFFFF */
+            "\"\xFC\x83\xBF\xBF\xBF\xBF\"",
+            NULL,                               /* bug: rejected */
+            "\"\\uC0FF\\uFFFF\\uFFFF\\uFFFF\"", /* bug: want "\"\\uFFFF\"" */
+            "\xFC\x83\xBF\xBF\xBF\xBF",
+        },
+        /* 4.3  Overlong representation of the NUL character */
+        {
+            /* \U+0000 */
+            "\"\xC0\x80\"",
+            NULL,               /* bug: rejected */
+            "\"\\u0000\"",
+            "\xC0\x80",
+        },
+        {
+            /* \U+0000 */
+            "\"\xE0\x80\x80\"",
+            "\xE0\x80\x80",     /* bug: not corrected */
+            "\"\\u0000\"",
+        },
+        {
+            /* \U+0000 */
+            "\"\xF0\x80\x80\x80\"",
+            "\xF0\x80\x80\x80",   /* bug: not corrected */
+            "\"\\u0000\\uFFFF\"", /* bug: want "\"\\u0000\"" */
+        },
+        {
+            /* \U+0000 */
+            "\"\xF8\x80\x80\x80\x80\"",
+            NULL,                        /* bug: rejected */
+            "\"\\u8000\\uFFFF\\uFFFF\"", /* bug: want "\"\\u0000\"" */
+            "\xF8\x80\x80\x80\x80",
+        },
+        {
+            /* \U+0000 */
+            "\"\xFC\x80\x80\x80\x80\x80\"",
+            NULL,                               /* bug: rejected */
+            "\"\\uC000\\uFFFF\\uFFFF\\uFFFF\"", /* bug: want "\"\\u0000\"" */
+            "\xFC\x80\x80\x80\x80\x80",
+        },
+        /* 5  Illegal code positions */
+        /* 5.1  Single UTF-16 surrogates */
+        {
+            /* \U+D800 */
+            "\"\xED\xA0\x80\"",
+            "\xED\xA0\x80",     /* bug: not corrected */
+            "\"\\uD800\"",      /* bug: want "\"\\uFFFF\"" */
+        },
+        {
+            /* \U+DB7F */
+            "\"\xED\xAD\xBF\"",
+            "\xED\xAD\xBF",     /* bug: not corrected */
+            "\"\\uDB7F\"",      /* bug: want "\"\\uFFFF\"" */
+        },
+        {
+            /* \U+DB80 */
+            "\"\xED\xAE\x80\"",
+            "\xED\xAE\x80",     /* bug: not corrected */
+            "\"\\uDB80\"",      /* bug: want "\"\\uFFFF\"" */
+        },
+        {
+            /* \U+DBFF */
+            "\"\xED\xAF\xBF\"",
+            "\xED\xAF\xBF",     /* bug: not corrected */
+            "\"\\uDBFF\"",      /* bug: want "\"\\uFFFF\"" */
+        },
+        {
+            /* \U+DC00 */
+            "\"\xED\xB0\x80\"",
+            "\xED\xB0\x80",     /* bug: not corrected */
+            "\"\\uDC00\"",      /* bug: want "\"\\uFFFF\"" */
+        },
+        {
+            /* \U+DF80 */
+            "\"\xED\xBE\x80\"",
+            "\xED\xBE\x80",     /* bug: not corrected */
+            "\"\\uDF80\"",      /* bug: want "\"\\uFFFF\"" */
+        },
+        {
+            /* \U+DFFF */
+            "\"\xED\xBF\xBF\"",
+            "\xED\xBF\xBF",     /* bug: not corrected */
+            "\"\\uDFFF\"",      /* bug: want "\"\\uFFFF\"" */
+        },
+        /* 5.2  Paired UTF-16 surrogates */
+        {
+            /* \U+D800\U+DC00 */
+            "\"\xED\xA0\x80\xED\xB0\x80\"",
+            "\xED\xA0\x80\xED\xB0\x80", /* bug: not corrected */
+            "\"\\uD800\\uDC00\"", /* bug: want "\"\\uFFFF\\uFFFF\"" */
+        },
+        {
+            /* \U+D800\U+DFFF */
+            "\"\xED\xA0\x80\xED\xBF\xBF\"",
+            "\xED\xA0\x80\xED\xBF\xBF", /* bug: not corrected */
+            "\"\\uD800\\uDFFF\"", /* bug: want "\"\\uFFFF\\uFFFF\"" */
+        },
+        {
+            /* \U+DB7F\U+DC00 */
+            "\"\xED\xAD\xBF\xED\xB0\x80\"",
+            "\xED\xAD\xBF\xED\xB0\x80", /* bug: not corrected */
+            "\"\\uDB7F\\uDC00\"", /* bug: want "\"\\uFFFF\\uFFFF\"" */
+        },
+        {
+            /* \U+DB7F\U+DFFF */
+            "\"\xED\xAD\xBF\xED\xBF\xBF\"",
+            "\xED\xAD\xBF\xED\xBF\xBF", /* bug: not corrected */
+            "\"\\uDB7F\\uDFFF\"", /* bug: want "\"\\uFFFF\\uFFFF\"" */
+        },
+        {
+            /* \U+DB80\U+DC00 */
+            "\"\xED\xAE\x80\xED\xB0\x80\"",
+            "\xED\xAE\x80\xED\xB0\x80", /* bug: not corrected */
+            "\"\\uDB80\\uDC00\"", /* bug: want "\"\\uFFFF\\uFFFF\"" */
+        },
+        {
+            /* \U+DB80\U+DFFF */
+            "\"\xED\xAE\x80\xED\xBF\xBF\"",
+            "\xED\xAE\x80\xED\xBF\xBF", /* bug: not corrected */
+            "\"\\uDB80\\uDFFF\"", /* bug: want "\"\\uFFFF\\uFFFF\"" */
+        },
+        {
+            /* \U+DBFF\U+DC00 */
+            "\"\xED\xAF\xBF\xED\xB0\x80\"",
+            "\xED\xAF\xBF\xED\xB0\x80", /* bug: not corrected */
+            "\"\\uDBFF\\uDC00\"", /* bug: want "\"\\uFFFF\\uFFFF\"" */
+        },
+        {
+            /* \U+DBFF\U+DFFF */
+            "\"\xED\xAF\xBF\xED\xBF\xBF\"",
+            "\xED\xAF\xBF\xED\xBF\xBF", /* bug: not corrected */
+            "\"\\uDBFF\\uDFFF\"", /* bug: want "\"\\uFFFF\\uFFFF\"" */
+        },
+        /* 5.3  Other illegal code positions */
+        {
+            /* \U+FFFE */
+            "\"\xEF\xBF\xBE\"",
+            "\xEF\xBF\xBE",     /* bug: not corrected */
+            "\"\\uFFFE\"",      /* bug: not corrected */
+        },
+        {
+            /* \U+FFFF */
+            "\"\xEF\xBF\xBF\"",
+            "\xEF\xBF\xBF",     /* bug: not corrected */
+            "\"\\uFFFF\"",      /* bug: not corrected */
+        },
+        {}
+    };
+    int i;
+    QObject *obj;
+    QString *str;
+    const char *json_in, *utf8_out, *utf8_in, *json_out;
+
+    for (i = 0; test_cases[i].json_in; i++) {
+        json_in = test_cases[i].json_in;
+        utf8_out = test_cases[i].utf8_out;
+        utf8_in = test_cases[i].utf8_in ?: test_cases[i].utf8_out;
+        json_out = test_cases[i].json_out ?: test_cases[i].json_in;
+
+        obj = qobject_from_json(json_in);
+        if (utf8_out) {
+            g_assert(obj);
+            g_assert(qobject_type(obj) == QTYPE_QSTRING);
+            str = qobject_to_qstring(obj);
+            g_assert_cmpstr(qstring_get_str(str), ==, utf8_out);
+        } else {
+            g_assert(!obj);
+        }
+        qobject_decref(obj);
+
+        obj = QOBJECT(qstring_from_str(utf8_in));
+        str = qobject_to_json(obj);
+        if (json_out) {
+            g_assert(str);
+            g_assert_cmpstr(qstring_get_str(str), ==, json_out);
+        } else {
+            g_assert(!str);
+        }
+        QDECREF(str);
+        qobject_decref(obj);
+
+        /*
+         * Disabled, because json_out currently contains the crap
+         * qobject_to_json() produces.
+         * FIXME Enable once these bugs have been fixed.
+         */
+        if (0 && json_out != json_in) {
+            obj = qobject_from_json(json_out);
+            g_assert(obj);
+            g_assert(qobject_type(obj) == QTYPE_QSTRING);
+            str = qobject_to_qstring(obj);
+            g_assert_cmpstr(qstring_get_str(str), ==, utf8_out);
+        }
+    }
+}
+
 static void vararg_string(void)
 {
     int i;
@@ -748,6 +1411,7 @@ int main(int argc, char **argv)
 
     g_test_add_func("/literals/string/simple", simple_string);
     g_test_add_func("/literals/string/escaped", escaped_string);
+    g_test_add_func("/literals/string/utf8", utf8_string);
     g_test_add_func("/literals/string/single_quote", single_quote_string);
     g_test_add_func("/literals/string/vararg", vararg_string);