Adding upstream version 2:9.0.1378.upstream/2%9.0.1378upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1277 insertions, 0 deletions

diff --git a/src/json.c b/src/json.c
new file mode 100644
index 0000000..9c084b4
--- /dev/null
+++ b/src/json.c
@@ -0,0 +1,1277 @@
+/* vi:set ts=8 sts=4 sw=4 noet:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read copying and usage conditions.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ * See README.txt for an overview of the Vim source code.
+ */
+
+/*
+ * json.c: Encoding and decoding JSON.
+ *
+ * Follows this standard: https://tools.ietf.org/html/rfc7159.html
+ */
+#define USING_FLOAT_STUFF
+
+#include "vim.h"
+
+#if defined(FEAT_EVAL) || defined(PROTO)
+
+static int json_encode_item(garray_T *gap, typval_T *val, int copyID, int options);
+
+/*
+ * Encode "val" into a JSON format string.
+ * The result is added to "gap"
+ * Returns FAIL on failure and makes gap->ga_data empty.
+ */
+    static int
+json_encode_gap(garray_T *gap, typval_T *val, int options)
+{
+    if (json_encode_item(gap, val, get_copyID(), options) == FAIL)
+    {
+	ga_clear(gap);
+	gap->ga_data = vim_strsave((char_u *)"");
+	return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * Encode "val" into a JSON format string.
+ * The result is in allocated memory.
+ * The result is empty when encoding fails.
+ * "options" can contain JSON_JS, JSON_NO_NONE and JSON_NL.
+ */
+    char_u *
+json_encode(typval_T *val, int options)
+{
+    garray_T ga;
+
+    // Store bytes in the growarray.
+    ga_init2(&ga, 1, 4000);
+    json_encode_gap(&ga, val, options);
+    ga_append(&ga, NUL);
+    return ga.ga_data;
+}
+
+#if defined(FEAT_JOB_CHANNEL) || defined(PROTO)
+/*
+ * Encode ["nr", "val"] into a JSON format string in allocated memory.
+ * "options" can contain JSON_JS, JSON_NO_NONE and JSON_NL.
+ * Returns NULL when out of memory.
+ */
+    char_u *
+json_encode_nr_expr(int nr, typval_T *val, int options)
+{
+    typval_T	listtv;
+    typval_T	nrtv;
+    garray_T	ga;
+
+    nrtv.v_type = VAR_NUMBER;
+    nrtv.vval.v_number = nr;
+    if (rettv_list_alloc(&listtv) == FAIL)
+	return NULL;
+    if (list_append_tv(listtv.vval.v_list, &nrtv) == FAIL
+	    || list_append_tv(listtv.vval.v_list, val) == FAIL)
+    {
+	list_unref(listtv.vval.v_list);
+	return NULL;
+    }
+
+    ga_init2(&ga, 1, 4000);
+    if (json_encode_gap(&ga, &listtv, options) == OK && (options & JSON_NL))
+	ga_append(&ga, '\n');
+    list_unref(listtv.vval.v_list);
+    ga_append(&ga, NUL);
+    return ga.ga_data;
+}
+
+/*
+ * Encode "val" into a JSON format string prefixed by the LSP HTTP header.
+ * Returns NULL when out of memory.
+ */
+    char_u *
+json_encode_lsp_msg(typval_T *val)
+{
+    garray_T	ga;
+    garray_T	lspga;
+
+    ga_init2(&ga, 1, 4000);
+    if (json_encode_gap(&ga, val, 0) == FAIL)
+	return NULL;
+    ga_append(&ga, NUL);
+
+    ga_init2(&lspga, 1, 4000);
+    vim_snprintf((char *)IObuff, IOSIZE,
+	    "Content-Length: %u\r\n"
+	    "Content-Type: application/vim-jsonrpc; charset=utf-8\r\n\r\n",
+	    ga.ga_len - 1);
+    ga_concat(&lspga, IObuff);
+    ga_concat_len(&lspga, ga.ga_data, ga.ga_len);
+    ga_clear(&ga);
+    return lspga.ga_data;
+}
+#endif
+
+/*
+ * Lookup table to quickly know if the given ASCII character must be escaped.
+ */
+static const char ascii_needs_escape[128] = {
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 0x0.
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 0x1.
+    0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0x2.
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0x3.
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0x4.
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, // 0x5.
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0x6.
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0x7.
+};
+
+/*
+ * Encode the utf-8 encoded string "str" into "gap".
+ */
+    static void
+write_string(garray_T *gap, char_u *str)
+{
+    char_u	*res = str;
+    char_u	numbuf[NUMBUFLEN];
+    char_u	*from;
+#if defined(USE_ICONV)
+    vimconv_T   conv;
+    char_u	*converted = NULL;
+#endif
+    int		c;
+
+    if (res == NULL)
+    {
+	ga_concat(gap, (char_u *)"\"\"");
+	return;
+    }
+
+#if defined(USE_ICONV)
+    if (!enc_utf8)
+    {
+	// Convert the text from 'encoding' to utf-8, because a JSON string is
+	// always utf-8.
+	conv.vc_type = CONV_NONE;
+	convert_setup(&conv, p_enc, (char_u*)"utf-8");
+	if (conv.vc_type != CONV_NONE)
+	    converted = res = string_convert(&conv, res, NULL);
+	convert_setup(&conv, NULL, NULL);
+    }
+#endif
+    ga_append(gap, '"');
+    // `from` is the beginning of a sequence of bytes we can directly copy from
+    // the input string, avoiding the overhead associated to decoding/encoding
+    // them.
+    from = res;
+    while ((c = *res) != NUL)
+    {
+	// always use utf-8 encoding, ignore 'encoding'
+	if (c < 0x80)
+	{
+	    if (!ascii_needs_escape[c])
+	    {
+		res += 1;
+		continue;
+	    }
+
+	    if (res != from)
+		ga_concat_len(gap, from, res - from);
+	    from = res + 1;
+
+	    switch (c)
+	    {
+		case 0x08:
+		    ga_append(gap, '\\'); ga_append(gap, 'b'); break;
+		case 0x09:
+		    ga_append(gap, '\\'); ga_append(gap, 't'); break;
+		case 0x0a:
+		    ga_append(gap, '\\'); ga_append(gap, 'n'); break;
+		case 0x0c:
+		    ga_append(gap, '\\'); ga_append(gap, 'f'); break;
+		case 0x0d:
+		    ga_append(gap, '\\'); ga_append(gap, 'r'); break;
+		case 0x22: // "
+		case 0x5c: // backslash
+		    ga_append(gap, '\\');
+		    ga_append(gap, c);
+		    break;
+		default:
+		    vim_snprintf((char *)numbuf, NUMBUFLEN, "\\u%04lx",
+								      (long)c);
+		    ga_concat(gap, numbuf);
+	    }
+
+	    res += 1;
+	}
+	else
+	{
+	    int l = utf_ptr2len(res);
+
+	    if (l > 1)
+	    {
+		res += l;
+		continue;
+	    }
+
+	    // Invalid utf-8 sequence, replace it with the Unicode replacement
+	    // character U+FFFD.
+	    if (res != from)
+		ga_concat_len(gap, from, res - from);
+	    from = res + 1;
+
+	    numbuf[utf_char2bytes(0xFFFD, numbuf)] = NUL;
+	    ga_concat(gap, numbuf);
+
+	    res += l;
+	}
+    }
+
+    if (res != from)
+	ga_concat_len(gap, from, res - from);
+
+    ga_append(gap, '"');
+#if defined(USE_ICONV)
+    vim_free(converted);
+#endif
+}
+
+/*
+ * Return TRUE if "key" can be used without quotes.
+ * That is when it starts with a letter and only contains letters, digits and
+ * underscore.
+ */
+    static int
+is_simple_key(char_u *key)
+{
+    char_u *p;
+
+    if (!ASCII_ISALPHA(*key))
+	return FALSE;
+    for (p = key + 1; *p != NUL; ++p)
+	if (!ASCII_ISALPHA(*p) && *p != '_' && !vim_isdigit(*p))
+	    return FALSE;
+    return TRUE;
+}
+
+/*
+ * Encode "val" into "gap".
+ * Return FAIL or OK.
+ */
+    static int
+json_encode_item(garray_T *gap, typval_T *val, int copyID, int options)
+{
+    char_u	numbuf[NUMBUFLEN];
+    char_u	*res;
+    blob_T	*b;
+    list_T	*l;
+    dict_T	*d;
+    int		i;
+
+    switch (val->v_type)
+    {
+	case VAR_BOOL:
+	    switch ((long)val->vval.v_number)
+	    {
+		case VVAL_FALSE: ga_concat(gap, (char_u *)"false"); break;
+		case VVAL_TRUE: ga_concat(gap, (char_u *)"true"); break;
+	    }
+	    break;
+
+	case VAR_SPECIAL:
+	    switch ((long)val->vval.v_number)
+	    {
+		case VVAL_NONE: if ((options & JSON_JS) != 0
+					     && (options & JSON_NO_NONE) == 0)
+				    // empty item
+				    break;
+				// FALLTHROUGH
+		case VVAL_NULL: ga_concat(gap, (char_u *)"null"); break;
+	    }
+	    break;
+
+	case VAR_NUMBER:
+	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%lld",
+					      (varnumber_T)val->vval.v_number);
+	    ga_concat(gap, numbuf);
+	    break;
+
+	case VAR_STRING:
+	    res = val->vval.v_string;
+	    write_string(gap, res);
+	    break;
+
+	case VAR_FUNC:
+	case VAR_PARTIAL:
+	case VAR_JOB:
+	case VAR_CHANNEL:
+	case VAR_INSTR:
+	case VAR_CLASS:
+	case VAR_OBJECT:
+	    semsg(_(e_cannot_json_encode_str), vartype_name(val->v_type));
+	    return FAIL;
+
+	case VAR_BLOB:
+	    b = val->vval.v_blob;
+	    if (b == NULL || b->bv_ga.ga_len == 0)
+		ga_concat(gap, (char_u *)"[]");
+	    else
+	    {
+		ga_append(gap, '[');
+		for (i = 0; i < b->bv_ga.ga_len; i++)
+		{
+		    if (i > 0)
+			ga_concat(gap, (char_u *)",");
+		    vim_snprintf((char *)numbuf, NUMBUFLEN, "%d",
+			    blob_get(b, i));
+		    ga_concat(gap, numbuf);
+		}
+		ga_append(gap, ']');
+	    }
+	    break;
+
+	case VAR_LIST:
+	    l = val->vval.v_list;
+	    if (l == NULL)
+		ga_concat(gap, (char_u *)"[]");
+	    else
+	    {
+		if (l->lv_copyID == copyID)
+		    ga_concat(gap, (char_u *)"[]");
+		else
+		{
+		    listitem_T	*li;
+
+		    l->lv_copyID = copyID;
+		    ga_append(gap, '[');
+		    CHECK_LIST_MATERIALIZE(l);
+		    for (li = l->lv_first; li != NULL && !got_int; )
+		    {
+			if (json_encode_item(gap, &li->li_tv, copyID,
+						   options & JSON_JS) == FAIL)
+			    return FAIL;
+			if ((options & JSON_JS)
+				&& li->li_next == NULL
+				&& li->li_tv.v_type == VAR_SPECIAL
+				&& li->li_tv.vval.v_number == VVAL_NONE)
+			    // add an extra comma if the last item is v:none
+			    ga_append(gap, ',');
+			li = li->li_next;
+			if (li != NULL)
+			    ga_append(gap, ',');
+		    }
+		    ga_append(gap, ']');
+		    l->lv_copyID = 0;
+		}
+	    }
+	    break;
+
+	case VAR_DICT:
+	    d = val->vval.v_dict;
+	    if (d == NULL)
+		ga_concat(gap, (char_u *)"{}");
+	    else
+	    {
+		if (d->dv_copyID == copyID)
+		    ga_concat(gap, (char_u *)"{}");
+		else
+		{
+		    int		first = TRUE;
+		    int		todo = (int)d->dv_hashtab.ht_used;
+		    hashitem_T	*hi;
+
+		    d->dv_copyID = copyID;
+		    ga_append(gap, '{');
+
+		    for (hi = d->dv_hashtab.ht_array; todo > 0 && !got_int;
+									 ++hi)
+			if (!HASHITEM_EMPTY(hi))
+			{
+			    --todo;
+			    if (first)
+				first = FALSE;
+			    else
+				ga_append(gap, ',');
+			    if ((options & JSON_JS)
+						 && is_simple_key(hi->hi_key))
+				ga_concat(gap, hi->hi_key);
+			    else
+				write_string(gap, hi->hi_key);
+			    ga_append(gap, ':');
+			    if (json_encode_item(gap, &dict_lookup(hi)->di_tv,
+				      copyID, options | JSON_NO_NONE) == FAIL)
+				return FAIL;
+			}
+		    ga_append(gap, '}');
+		    d->dv_copyID = 0;
+		}
+	    }
+	    break;
+
+	case VAR_FLOAT:
+#if defined(HAVE_MATH_H)
+	    if (isnan(val->vval.v_float))
+		ga_concat(gap, (char_u *)"NaN");
+	    else if (isinf(val->vval.v_float))
+	    {
+		if (val->vval.v_float < 0.0)
+		    ga_concat(gap, (char_u *)"-Infinity");
+		else
+		    ga_concat(gap, (char_u *)"Infinity");
+	    }
+	    else
+#endif
+	    {
+		vim_snprintf((char *)numbuf, NUMBUFLEN, "%g",
+							   val->vval.v_float);
+		ga_concat(gap, numbuf);
+	    }
+	    break;
+	case VAR_UNKNOWN:
+	case VAR_ANY:
+	case VAR_VOID:
+	    internal_error_no_abort("json_encode_item()");
+	    return FAIL;
+    }
+    return OK;
+}
+
+/*
+ * When "reader" has less than NUMBUFLEN bytes available, call the fill
+ * callback to get more.
+ */
+    static void
+fill_numbuflen(js_read_T *reader)
+{
+    if (reader->js_fill != NULL && (int)(reader->js_end - reader->js_buf)
+						- reader->js_used < NUMBUFLEN)
+    {
+	if (reader->js_fill(reader))
+	    reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
+    }
+}
+
+/*
+ * Skip white space in "reader".  All characters <= space are considered white
+ * space.
+ * Also tops up readahead when needed.
+ */
+    static void
+json_skip_white(js_read_T *reader)
+{
+    int c;
+
+    for (;;)
+    {
+	c = reader->js_buf[reader->js_used];
+	if (reader->js_fill != NULL && c == NUL)
+	{
+	    if (reader->js_fill(reader))
+	    {
+		reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
+		continue;
+	    }
+	}
+	if (c == NUL || c > ' ')
+	    break;
+	++reader->js_used;
+    }
+    fill_numbuflen(reader);
+}
+
+    static int
+json_decode_string(js_read_T *reader, typval_T *res, int quote)
+{
+    garray_T    ga;
+    int		len;
+    char_u	*p;
+    int		c;
+    varnumber_T	nr;
+
+    if (res != NULL)
+	ga_init2(&ga, 1, 200);
+
+    p = reader->js_buf + reader->js_used + 1; // skip over " or '
+    while (*p != quote)
+    {
+	// The JSON is always expected to be utf-8, thus use utf functions
+	// here. The string is converted below if needed.
+	if (*p == NUL || p[1] == NUL || utf_ptr2len(p) < utf_byte2len(*p))
+	{
+	    // Not enough bytes to make a character or end of the string. Get
+	    // more if possible.
+	    if (reader->js_fill == NULL)
+		break;
+	    len = (int)(reader->js_end - p);
+	    reader->js_used = (int)(p - reader->js_buf);
+	    if (!reader->js_fill(reader))
+		break; // didn't get more
+	    p = reader->js_buf + reader->js_used;
+	    reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
+	    continue;
+	}
+
+	if (*p == '\\')
+	{
+	    c = -1;
+	    switch (p[1])
+	    {
+		case '\\': c = '\\'; break;
+		case '"': c = '"'; break;
+		case 'b': c = BS; break;
+		case 't': c = TAB; break;
+		case 'n': c = NL; break;
+		case 'f': c = FF; break;
+		case 'r': c = CAR; break;
+		case 'u':
+		    if (reader->js_fill != NULL
+				     && (int)(reader->js_end - p) < NUMBUFLEN)
+		    {
+			reader->js_used = (int)(p - reader->js_buf);
+			if (reader->js_fill(reader))
+			{
+			    p = reader->js_buf + reader->js_used;
+			    reader->js_end = reader->js_buf
+						     + STRLEN(reader->js_buf);
+			}
+		    }
+		    nr = 0;
+		    len = 0;
+		    vim_str2nr(p + 2, NULL, &len,
+			     STR2NR_HEX + STR2NR_FORCE, &nr, NULL, 4, TRUE);
+		    if (len == 0)
+		    {
+			if (res != NULL)
+			    ga_clear(&ga);
+			return FAIL;
+		    }
+		    p += len + 2;
+		    if (0xd800 <= nr && nr <= 0xdfff
+			    && (int)(reader->js_end - p) >= 6
+			    && *p == '\\' && *(p+1) == 'u')
+		    {
+			varnumber_T	nr2 = 0;
+
+			// decode surrogate pair: \ud812\u3456
+			len = 0;
+			vim_str2nr(p + 2, NULL, &len,
+			     STR2NR_HEX + STR2NR_FORCE, &nr2, NULL, 4, TRUE);
+			if (len == 0)
+			{
+			    if (res != NULL)
+				ga_clear(&ga);
+			    return FAIL;
+			}
+			if (0xdc00 <= nr2 && nr2 <= 0xdfff)
+			{
+			    p += len + 2;
+			    nr = (((nr - 0xd800) << 10) |
+				((nr2 - 0xdc00) & 0x3ff)) + 0x10000;
+			}
+		    }
+		    if (res != NULL)
+		    {
+			char_u	buf[NUMBUFLEN];
+
+			buf[utf_char2bytes((int)nr, buf)] = NUL;
+			ga_concat(&ga, buf);
+		    }
+		    break;
+		default:
+		    // not a special char, skip over backslash
+		    ++p;
+		    continue;
+	    }
+	    if (c > 0)
+	    {
+		p += 2;
+		if (res != NULL)
+		    ga_append(&ga, c);
+	    }
+	}
+	else
+	{
+	    len = utf_ptr2len(p);
+	    if (res != NULL)
+	    {
+		if (ga_grow(&ga, len) == FAIL)
+		{
+		    ga_clear(&ga);
+		    return FAIL;
+		}
+		mch_memmove((char *)ga.ga_data + ga.ga_len, p, (size_t)len);
+		ga.ga_len += len;
+	    }
+	    p += len;
+	}
+    }
+
+    reader->js_used = (int)(p - reader->js_buf);
+    if (*p == quote)
+    {
+	++reader->js_used;
+	if (res != NULL)
+	{
+	    ga_append(&ga, NUL);
+	    res->v_type = VAR_STRING;
+#if defined(USE_ICONV)
+	    if (!enc_utf8)
+	    {
+		vimconv_T   conv;
+
+		// Convert the utf-8 string to 'encoding'.
+		conv.vc_type = CONV_NONE;
+		convert_setup(&conv, (char_u*)"utf-8", p_enc);
+		if (conv.vc_type != CONV_NONE)
+		{
+		    res->vval.v_string =
+				      string_convert(&conv, ga.ga_data, NULL);
+		    vim_free(ga.ga_data);
+		}
+		convert_setup(&conv, NULL, NULL);
+	    }
+	    else
+#endif
+		res->vval.v_string = ga.ga_data;
+	}
+	return OK;
+    }
+    if (res != NULL)
+    {
+	res->v_type = VAR_SPECIAL;
+	res->vval.v_number = VVAL_NONE;
+	ga_clear(&ga);
+    }
+    return MAYBE;
+}
+
+typedef enum {
+    JSON_ARRAY,		// parsing items in an array
+    JSON_OBJECT_KEY,	// parsing key of an object
+    JSON_OBJECT		// parsing item in an object, after the key
+} json_decode_T;
+
+typedef struct {
+    json_decode_T jd_type;
+    typval_T	  jd_tv;	// the list or dict
+    typval_T	  jd_key_tv;
+    char_u	  *jd_key;
+} json_dec_item_T;
+
+/*
+ * Decode one item and put it in "res".  If "res" is NULL only advance.
+ * Must already have skipped white space.
+ *
+ * Return FAIL for a decoding error (and give an error).
+ * Return MAYBE for an incomplete message.
+ */
+    static int
+json_decode_item(js_read_T *reader, typval_T *res, int options)
+{
+    char_u	*p;
+    int		i;
+    int		len;
+    int		retval;
+    garray_T	stack;
+    typval_T	item;
+    typval_T	*cur_item;
+    json_dec_item_T *top_item;
+    char_u	key_buf[NUMBUFLEN];
+
+    ga_init2(&stack, sizeof(json_dec_item_T), 100);
+    cur_item = res;
+    init_tv(&item);
+    if (res != NULL)
+	init_tv(res);
+
+    fill_numbuflen(reader);
+    p = reader->js_buf + reader->js_used;
+    for (;;)
+    {
+	top_item = NULL;
+	if (stack.ga_len > 0)
+	{
+	    top_item = ((json_dec_item_T *)stack.ga_data) + stack.ga_len - 1;
+	    json_skip_white(reader);
+	    p = reader->js_buf + reader->js_used;
+	    if (*p == NUL)
+	    {
+		retval = MAYBE;
+		goto theend;
+	    }
+	    if (top_item->jd_type == JSON_OBJECT_KEY
+					    || top_item->jd_type == JSON_ARRAY)
+	    {
+		// Check for end of object or array.
+		if (*p == (top_item->jd_type == JSON_ARRAY ? ']' : '}'))
+		{
+		    ++reader->js_used; // consume the ']' or '}'
+		    --stack.ga_len;
+		    if (stack.ga_len == 0)
+		    {
+			retval = OK;
+			goto theend;
+		    }
+		    if (cur_item != NULL)
+			cur_item = &top_item->jd_tv;
+		    goto item_end;
+		}
+	    }
+	}
+
+	if (top_item != NULL && top_item->jd_type == JSON_OBJECT_KEY
+		&& (options & JSON_JS)
+		&& reader->js_buf[reader->js_used] != '"'
+		&& reader->js_buf[reader->js_used] != '\''
+		&& reader->js_buf[reader->js_used] != '['
+		&& reader->js_buf[reader->js_used] != '{')
+	{
+	    char_u *key;
+
+	    // accept an object key that is not in quotes
+	    key = p = reader->js_buf + reader->js_used;
+	    while (*p != NUL && *p != ':' && *p > ' ')
+		++p;
+	    if (cur_item != NULL)
+	    {
+		cur_item->v_type = VAR_STRING;
+		cur_item->vval.v_string = vim_strnsave(key, p - key);
+		top_item->jd_key = cur_item->vval.v_string;
+	    }
+	    reader->js_used += (int)(p - key);
+	}
+	else
+	{
+	    switch (*p)
+	    {
+		case '[': // start of array
+		    if (top_item && top_item->jd_type == JSON_OBJECT_KEY)
+		    {
+			retval = FAIL;
+			break;
+		    }
+		    if (ga_grow(&stack, 1) == FAIL)
+		    {
+			retval = FAIL;
+			break;
+		    }
+		    if (cur_item != NULL && rettv_list_alloc(cur_item) == FAIL)
+		    {
+			cur_item->v_type = VAR_SPECIAL;
+			cur_item->vval.v_number = VVAL_NONE;
+			retval = FAIL;
+			break;
+		    }
+
+		    ++reader->js_used; // consume the '['
+		    top_item = ((json_dec_item_T *)stack.ga_data)
+								+ stack.ga_len;
+		    top_item->jd_type = JSON_ARRAY;
+		    ++stack.ga_len;
+		    if (cur_item != NULL)
+		    {
+			top_item->jd_tv = *cur_item;
+			cur_item = &item;
+		    }
+		    continue;
+
+		case '{': // start of object
+		    if (top_item && top_item->jd_type == JSON_OBJECT_KEY)
+		    {
+			retval = FAIL;
+			break;
+		    }
+		    if (ga_grow(&stack, 1) == FAIL)
+		    {
+			retval = FAIL;
+			break;
+		    }
+		    if (cur_item != NULL && rettv_dict_alloc(cur_item) == FAIL)
+		    {
+			cur_item->v_type = VAR_SPECIAL;
+			cur_item->vval.v_number = VVAL_NONE;
+			retval = FAIL;
+			break;
+		    }
+
+		    ++reader->js_used; // consume the '{'
+		    top_item = ((json_dec_item_T *)stack.ga_data)
+								+ stack.ga_len;
+		    top_item->jd_type = JSON_OBJECT_KEY;
+		    ++stack.ga_len;
+		    if (cur_item != NULL)
+		    {
+			top_item->jd_tv = *cur_item;
+			cur_item = &top_item->jd_key_tv;
+		    }
+		    continue;
+
+		case '"': // string
+		    retval = json_decode_string(reader, cur_item, *p);
+		    break;
+
+		case '\'':
+		    if (options & JSON_JS)
+			retval = json_decode_string(reader, cur_item, *p);
+		    else
+		    {
+			semsg(_(e_json_decode_error_at_str), p);
+			retval = FAIL;
+		    }
+		    break;
+
+		case ',': // comma: empty item
+		    if ((options & JSON_JS) == 0)
+		    {
+			semsg(_(e_json_decode_error_at_str), p);
+			retval = FAIL;
+			break;
+		    }
+		    // FALLTHROUGH
+		case NUL: // empty
+		    if (cur_item != NULL)
+		    {
+			cur_item->v_type = VAR_SPECIAL;
+			cur_item->vval.v_number = VVAL_NONE;
+		    }
+		    retval = OK;
+		    break;
+
+		default:
+		    if (VIM_ISDIGIT(*p) || (*p == '-'
+					&& (VIM_ISDIGIT(p[1]) || p[1] == NUL)))
+		    {
+			char_u  *sp = p;
+
+			if (*sp == '-')
+			{
+			    ++sp;
+			    if (*sp == NUL)
+			    {
+				retval = MAYBE;
+				break;
+			    }
+			    if (!VIM_ISDIGIT(*sp))
+			    {
+				semsg(_(e_json_decode_error_at_str), p);
+				retval = FAIL;
+				break;
+			    }
+			}
+			sp = skipdigits(sp);
+			if (*sp == '.' || *sp == 'e' || *sp == 'E')
+			{
+			    if (cur_item == NULL)
+			    {
+				float_T f;
+
+				len = string2float(p, &f, FALSE);
+			    }
+			    else
+			    {
+				cur_item->v_type = VAR_FLOAT;
+				len = string2float(p, &cur_item->vval.v_float,
+									FALSE);
+			    }
+			}
+			else
+			{
+			    varnumber_T nr;
+
+			    vim_str2nr(reader->js_buf + reader->js_used,
+				    NULL, &len, 0, // what
+				    &nr, NULL, 0, TRUE);
+			    if (len == 0)
+			    {
+				semsg(_(e_json_decode_error_at_str), p);
+				retval = FAIL;
+				goto theend;
+			    }
+			    if (cur_item != NULL)
+			    {
+				cur_item->v_type = VAR_NUMBER;
+				cur_item->vval.v_number = nr;
+			    }
+			}
+			reader->js_used += len;
+			retval = OK;
+			break;
+		    }
+		    if (STRNICMP((char *)p, "false", 5) == 0)
+		    {
+			reader->js_used += 5;
+			if (cur_item != NULL)
+			{
+			    cur_item->v_type = VAR_BOOL;
+			    cur_item->vval.v_number = VVAL_FALSE;
+			}
+			retval = OK;
+			break;
+		    }
+		    if (STRNICMP((char *)p, "true", 4) == 0)
+		    {
+			reader->js_used += 4;
+			if (cur_item != NULL)
+			{
+			    cur_item->v_type = VAR_BOOL;
+			    cur_item->vval.v_number = VVAL_TRUE;
+			}
+			retval = OK;
+			break;
+		    }
+		    if (STRNICMP((char *)p, "null", 4) == 0)
+		    {
+			reader->js_used += 4;
+			if (cur_item != NULL)
+			{
+			    cur_item->v_type = VAR_SPECIAL;
+			    cur_item->vval.v_number = VVAL_NULL;
+			}
+			retval = OK;
+			break;
+		    }
+		    if (STRNICMP((char *)p, "NaN", 3) == 0)
+		    {
+			reader->js_used += 3;
+			if (cur_item != NULL)
+			{
+			    cur_item->v_type = VAR_FLOAT;
+			    cur_item->vval.v_float = NAN;
+			}
+			retval = OK;
+			break;
+		    }
+		    if (STRNICMP((char *)p, "-Infinity", 9) == 0)
+		    {
+			reader->js_used += 9;
+			if (cur_item != NULL)
+			{
+			    cur_item->v_type = VAR_FLOAT;
+			    cur_item->vval.v_float = -INFINITY;
+			}
+			retval = OK;
+			break;
+		    }
+		    if (STRNICMP((char *)p, "Infinity", 8) == 0)
+		    {
+			reader->js_used += 8;
+			if (cur_item != NULL)
+			{
+			    cur_item->v_type = VAR_FLOAT;
+			    cur_item->vval.v_float = INFINITY;
+			}
+			retval = OK;
+			break;
+		    }
+		    // check for truncated name
+		    len = (int)(reader->js_end
+					 - (reader->js_buf + reader->js_used));
+		    if (
+			    (len < 5 && STRNICMP((char *)p, "false", len) == 0)
+			    || (len < 9
+				 && STRNICMP((char *)p, "-Infinity", len) == 0)
+			    || (len < 8
+				  && STRNICMP((char *)p, "Infinity", len) == 0)
+			    || (len < 3 && STRNICMP((char *)p, "NaN", len) == 0)
+			    || (len < 4
+				  && (STRNICMP((char *)p, "true", len) == 0
+				    || STRNICMP((char *)p, "null", len) == 0)))
+
+			retval = MAYBE;
+		    else
+			retval = FAIL;
+		    break;
+	    }
+
+	    // We are finished when retval is FAIL or MAYBE and when at the
+	    // toplevel.
+	    if (retval == FAIL)
+		break;
+	    if (retval == MAYBE || stack.ga_len == 0)
+		goto theend;
+
+	    if (top_item != NULL && top_item->jd_type == JSON_OBJECT_KEY
+		    && cur_item != NULL)
+	    {
+		if (cur_item->v_type == VAR_FLOAT)
+		{
+		    // cannot use a float as a key
+		    emsg(_(e_using_float_as_string));
+		    retval = FAIL;
+		    goto theend;
+		}
+		top_item->jd_key = tv_get_string_buf_chk(cur_item, key_buf);
+		if (top_item->jd_key == NULL)
+		{
+		    emsg(_(e_invalid_argument));
+		    retval = FAIL;
+		    goto theend;
+		}
+	    }
+	}
+
+item_end:
+	top_item = ((json_dec_item_T *)stack.ga_data) + stack.ga_len - 1;
+	switch (top_item->jd_type)
+	{
+	    case JSON_ARRAY:
+		if (res != NULL)
+		{
+		    listitem_T	*li = listitem_alloc();
+
+		    if (li == NULL)
+		    {
+			clear_tv(cur_item);
+			retval = FAIL;
+			goto theend;
+		    }
+		    li->li_tv = *cur_item;
+		    list_append(top_item->jd_tv.vval.v_list, li);
+		}
+		if (cur_item != NULL)
+		    cur_item = &item;
+
+		json_skip_white(reader);
+		p = reader->js_buf + reader->js_used;
+		if (*p == ',')
+		    ++reader->js_used;
+		else if (*p != ']')
+		{
+		    if (*p == NUL)
+			retval = MAYBE;
+		    else
+		    {
+			semsg(_(e_json_decode_error_at_str), p);
+			retval = FAIL;
+		    }
+		    goto theend;
+		}
+		break;
+
+	    case JSON_OBJECT_KEY:
+		json_skip_white(reader);
+		p = reader->js_buf + reader->js_used;
+		if (*p != ':')
+		{
+		    if (cur_item != NULL)
+			clear_tv(cur_item);
+		    if (*p == NUL)
+			retval = MAYBE;
+		    else
+		    {
+			semsg(_(e_json_decode_error_at_str), p);
+			retval = FAIL;
+		    }
+		    goto theend;
+		}
+		++reader->js_used;
+		json_skip_white(reader);
+		top_item->jd_type = JSON_OBJECT;
+		if (cur_item != NULL)
+		    cur_item = &item;
+		break;
+
+	    case JSON_OBJECT:
+		if (cur_item != NULL
+			&& dict_has_key(top_item->jd_tv.vval.v_dict,
+						(char *)top_item->jd_key))
+		{
+		    semsg(_(e_duplicate_key_in_json_str), top_item->jd_key);
+		    clear_tv(cur_item);
+		    retval = FAIL;
+		    goto theend;
+		}
+
+		if (cur_item != NULL)
+		{
+		    dictitem_T *di = dictitem_alloc(top_item->jd_key);
+
+		    clear_tv(&top_item->jd_key_tv);
+		    if (di == NULL)
+		    {
+			clear_tv(cur_item);
+			retval = FAIL;
+			goto theend;
+		    }
+		    di->di_tv = *cur_item;
+		    di->di_tv.v_lock = 0;
+		    if (dict_add(top_item->jd_tv.vval.v_dict, di) == FAIL)
+		    {
+			dictitem_free(di);
+			retval = FAIL;
+			goto theend;
+		    }
+		}
+
+		json_skip_white(reader);
+		p = reader->js_buf + reader->js_used;
+		if (*p == ',')
+		    ++reader->js_used;
+		else if (*p != '}')
+		{
+		    if (*p == NUL)
+			retval = MAYBE;
+		    else
+		    {
+			semsg(_(e_json_decode_error_at_str), p);
+			retval = FAIL;
+		    }
+		    goto theend;
+		}
+		top_item->jd_type = JSON_OBJECT_KEY;
+		if (cur_item != NULL)
+		    cur_item = &top_item->jd_key_tv;
+		break;
+	}
+    }
+
+    // Get here when parsing failed.
+    if (res != NULL)
+    {
+	clear_tv(res);
+	res->v_type = VAR_SPECIAL;
+	res->vval.v_number = VVAL_NONE;
+    }
+    semsg(_(e_json_decode_error_at_str), p);
+
+theend:
+    for (i = 0; i < stack.ga_len; i++)
+	clear_tv(&(((json_dec_item_T *)stack.ga_data) + i)->jd_key_tv);
+    ga_clear(&stack);
+
+    return retval;
+}
+
+/*
+ * Decode the JSON from "reader" and store the result in "res".
+ * "options" can be JSON_JS or zero;
+ * Return FAIL if not the whole message was consumed.
+ */
+    static int
+json_decode_all(js_read_T *reader, typval_T *res, int options)
+{
+    int ret;
+
+    // We find the end once, to avoid calling strlen() many times.
+    reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
+    json_skip_white(reader);
+    ret = json_decode_item(reader, res, options);
+    if (ret != OK)
+    {
+	if (ret == MAYBE)
+	    semsg(_(e_json_decode_error_at_str), reader->js_buf);
+	return FAIL;
+    }
+    json_skip_white(reader);
+    if (reader->js_buf[reader->js_used] != NUL)
+    {
+	semsg(_(e_trailing_characters_str), reader->js_buf + reader->js_used);
+	return FAIL;
+    }
+    return OK;
+}
+
+#if defined(FEAT_JOB_CHANNEL) || defined(PROTO)
+/*
+ * Decode the JSON from "reader" and store the result in "res".
+ * "options" can be JSON_JS or zero;
+ * Return FAIL for a decoding error.
+ * Return MAYBE for an incomplete message.
+ * Consumes the message anyway.
+ */
+    int
+json_decode(js_read_T *reader, typval_T *res, int options)
+{
+    int ret;
+
+    // We find the end once, to avoid calling strlen() many times.
+    reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
+    json_skip_white(reader);
+    ret = json_decode_item(reader, res, options);
+    json_skip_white(reader);
+
+    return ret;
+}
+#endif
+
+/*
+ * Decode the JSON from "reader" to find the end of the message.
+ * "options" can be JSON_JS or zero.
+ * This is only used for testing.
+ * Return FAIL if the message has a decoding error.
+ * Return MAYBE if the message is truncated, need to read more.
+ * This only works reliable if the message contains an object, array or
+ * string.  A number might be truncated without knowing.
+ * Does not advance the reader.
+ */
+    int
+json_find_end(js_read_T *reader, int options)
+{
+    int used_save = reader->js_used;
+    int ret;
+
+    // We find the end once, to avoid calling strlen() many times.
+    reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
+    json_skip_white(reader);
+    ret = json_decode_item(reader, NULL, options);
+    reader->js_used = used_save;
+    return ret;
+}
+
+/*
+ * "js_decode()" function
+ */
+    void
+f_js_decode(typval_T *argvars, typval_T *rettv)
+{
+    js_read_T	reader;
+
+    if (in_vim9script() && check_for_string_arg(argvars, 0) == FAIL)
+	return;
+
+    reader.js_buf = tv_get_string(&argvars[0]);
+    reader.js_fill = NULL;
+    reader.js_used = 0;
+    if (json_decode_all(&reader, rettv, JSON_JS) != OK)
+	emsg(_(e_invalid_argument));
+}
+
+/*
+ * "js_encode()" function
+ */
+    void
+f_js_encode(typval_T *argvars, typval_T *rettv)
+{
+    rettv->v_type = VAR_STRING;
+    rettv->vval.v_string = json_encode(&argvars[0], JSON_JS);
+}
+
+/*
+ * "json_decode()" function
+ */
+    void
+f_json_decode(typval_T *argvars, typval_T *rettv)
+{
+    js_read_T	reader;
+
+    if (in_vim9script() && check_for_string_arg(argvars, 0) == FAIL)
+	return;
+
+    reader.js_buf = tv_get_string(&argvars[0]);
+    reader.js_fill = NULL;
+    reader.js_used = 0;
+    json_decode_all(&reader, rettv, 0);
+}
+
+/*
+ * "json_encode()" function
+ */
+    void
+f_json_encode(typval_T *argvars, typval_T *rettv)
+{
+    rettv->v_type = VAR_STRING;
+    rettv->vval.v_string = json_encode(&argvars[0], 0);
+}
+#endif