view mercurial/cext/charencode.c @ 49779:7d6c8943353a stable

hg: show the correct message when cloning an LFS repo with extension disabled

The `extensions._disabledpaths()` doesn't handle fetching help from `__index__`,
so it returns an empty dictionary of paths.  That means None is always returned
from `extensions.disabled_help()` when embedding resources inside the pyoxidizer
or py2exe binary, regardless of the arg or if is an external extension stored in
the filesystem.  And that means wrongly telling the user with an explicitly
disabled LFS extension that it will be enabled locally upon cloning from an LFS
remote.  That causes test-lfs-serve.t:295 to fail.

This effectively reverts most of the rest of 843418dc0b1b, while keeping the
help text change in place (which was specifically identified as a problem).

/*
 charencode.c - miscellaneous character encoding

 Copyright 2008 Olivia Mackall <[e-mail]> and others

 This software may be used and distributed according to the terms of
 the GNU General Public License, incorporated herein by reference.
*/

#define PY_SSIZE_T_CLEAN
#include <Python.h>
#include <assert.h>

#include "charencode.h"
#include "compat.h"
#include "util.h"

/* clang-format off */
static const char lowertable[128] = {
	'\x00', '\x01', '\x02', '\x03', '\x04', '\x05', '\x06', '\x07',
	'\x08', '\x09', '\x0a', '\x0b', '\x0c', '\x0d', '\x0e', '\x0f',
	'\x10', '\x11', '\x12', '\x13', '\x14', '\x15', '\x16', '\x17',
	'\x18', '\x19', '\x1a', '\x1b', '\x1c', '\x1d', '\x1e', '\x1f',
	'\x20', '\x21', '\x22', '\x23', '\x24', '\x25', '\x26', '\x27',
	'\x28', '\x29', '\x2a', '\x2b', '\x2c', '\x2d', '\x2e', '\x2f',
	'\x30', '\x31', '\x32', '\x33', '\x34', '\x35', '\x36', '\x37',
	'\x38', '\x39', '\x3a', '\x3b', '\x3c', '\x3d', '\x3e', '\x3f',
	'\x40',
	        '\x61', '\x62', '\x63', '\x64', '\x65', '\x66', '\x67', /* A-G */
	'\x68', '\x69', '\x6a', '\x6b', '\x6c', '\x6d', '\x6e', '\x6f', /* H-O */
	'\x70', '\x71', '\x72', '\x73', '\x74', '\x75', '\x76', '\x77', /* P-W */
	'\x78', '\x79', '\x7a',                                         /* X-Z */
	                        '\x5b', '\x5c', '\x5d', '\x5e', '\x5f',
	'\x60', '\x61', '\x62', '\x63', '\x64', '\x65', '\x66', '\x67',
	'\x68', '\x69', '\x6a', '\x6b', '\x6c', '\x6d', '\x6e', '\x6f',
	'\x70', '\x71', '\x72', '\x73', '\x74', '\x75', '\x76', '\x77',
	'\x78', '\x79', '\x7a', '\x7b', '\x7c', '\x7d', '\x7e', '\x7f'
};

static const char uppertable[128] = {
	'\x00', '\x01', '\x02', '\x03', '\x04', '\x05', '\x06', '\x07',
	'\x08', '\x09', '\x0a', '\x0b', '\x0c', '\x0d', '\x0e', '\x0f',
	'\x10', '\x11', '\x12', '\x13', '\x14', '\x15', '\x16', '\x17',
	'\x18', '\x19', '\x1a', '\x1b', '\x1c', '\x1d', '\x1e', '\x1f',
	'\x20', '\x21', '\x22', '\x23', '\x24', '\x25', '\x26', '\x27',
	'\x28', '\x29', '\x2a', '\x2b', '\x2c', '\x2d', '\x2e', '\x2f',
	'\x30', '\x31', '\x32', '\x33', '\x34', '\x35', '\x36', '\x37',
	'\x38', '\x39', '\x3a', '\x3b', '\x3c', '\x3d', '\x3e', '\x3f',
	'\x40', '\x41', '\x42', '\x43', '\x44', '\x45', '\x46', '\x47',
	'\x48', '\x49', '\x4a', '\x4b', '\x4c', '\x4d', '\x4e', '\x4f',
	'\x50', '\x51', '\x52', '\x53', '\x54', '\x55', '\x56', '\x57',
	'\x58', '\x59', '\x5a', '\x5b', '\x5c', '\x5d', '\x5e', '\x5f',
	'\x60',
		'\x41', '\x42', '\x43', '\x44', '\x45', '\x46', '\x47', /* a-g */
	'\x48', '\x49', '\x4a', '\x4b', '\x4c', '\x4d', '\x4e', '\x4f', /* h-o */
	'\x50', '\x51', '\x52', '\x53', '\x54', '\x55', '\x56', '\x57', /* p-w */
	'\x58', '\x59', '\x5a', 					/* x-z */
				'\x7b', '\x7c', '\x7d', '\x7e', '\x7f'
};

/* 1: no escape, 2: \<c>, 6: \u<x> */
static const uint8_t jsonlentable[256] = {
	6, 6, 6, 6, 6, 6, 6, 6, 2, 2, 2, 6, 2, 2, 6, 6, /* b, t, n, f, r */
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* " */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, /* \\ */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, /* DEL */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
};

static const uint8_t jsonparanoidlentable[128] = {
	6, 6, 6, 6, 6, 6, 6, 6, 2, 2, 2, 6, 2, 2, 6, 6, /* b, t, n, f, r */
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* " */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, 1, 6, 1, /* <, > */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, /* \\ */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, /* DEL */
};

static const char hexchartable[16] = {
	'0', '1', '2', '3', '4', '5', '6', '7',
	'8', '9', 'a', 'b', 'c', 'd', 'e', 'f',
};
/* clang-format on */

/*
 * Turn a hex-encoded string into binary.
 */
PyObject *unhexlify(const char *str, Py_ssize_t len)
{
	PyObject *ret;
	char *d;
	Py_ssize_t i;

	ret = PyBytes_FromStringAndSize(NULL, len / 2);

	if (!ret) {
		return NULL;
	}

	d = PyBytes_AsString(ret);

	for (i = 0; i < len;) {
		int hi = hexdigit(str, i++);
		int lo = hexdigit(str, i++);
		*d++ = (hi << 4) | lo;
	}

	return ret;
}

PyObject *isasciistr(PyObject *self, PyObject *args)
{
	const char *buf;
	Py_ssize_t i, len;
	if (!PyArg_ParseTuple(args, "y#:isasciistr", &buf, &len)) {
		return NULL;
	}
	i = 0;
	/* char array in PyStringObject should be at least 4-byte aligned */
	if (((uintptr_t)buf & 3) == 0) {
		const uint32_t *p = (const uint32_t *)buf;
		for (; i < len / 4; i++) {
			if (p[i] & 0x80808080U) {
				Py_RETURN_FALSE;
			}
		}
		i *= 4;
	}
	for (; i < len; i++) {
		if (buf[i] & 0x80) {
			Py_RETURN_FALSE;
		}
	}
	Py_RETURN_TRUE;
}

static inline PyObject *
_asciitransform(PyObject *str_obj, const char table[128], PyObject *fallback_fn)
{
	char *str, *newstr;
	Py_ssize_t i, len;
	PyObject *newobj = NULL;
	PyObject *ret = NULL;

	str = PyBytes_AS_STRING(str_obj);
	len = PyBytes_GET_SIZE(str_obj);

	newobj = PyBytes_FromStringAndSize(NULL, len);
	if (!newobj) {
		goto quit;
	}

	newstr = PyBytes_AS_STRING(newobj);

	for (i = 0; i < len; i++) {
		char c = str[i];
		if (c & 0x80) {
			if (fallback_fn != NULL) {
				ret = PyObject_CallFunctionObjArgs(
				    fallback_fn, str_obj, NULL);
			} else {
				PyObject *err = PyUnicodeDecodeError_Create(
				    "ascii", str, len, i, (i + 1),
				    "unexpected code byte");
				PyErr_SetObject(PyExc_UnicodeDecodeError, err);
				Py_XDECREF(err);
			}
			goto quit;
		}
		newstr[i] = table[(unsigned char)c];
	}

	ret = newobj;
	Py_INCREF(ret);
quit:
	Py_XDECREF(newobj);
	return ret;
}

PyObject *asciilower(PyObject *self, PyObject *args)
{
	PyObject *str_obj;
	if (!PyArg_ParseTuple(args, "O!:asciilower", &PyBytes_Type, &str_obj)) {
		return NULL;
	}
	return _asciitransform(str_obj, lowertable, NULL);
}

PyObject *asciiupper(PyObject *self, PyObject *args)
{
	PyObject *str_obj;
	if (!PyArg_ParseTuple(args, "O!:asciiupper", &PyBytes_Type, &str_obj)) {
		return NULL;
	}
	return _asciitransform(str_obj, uppertable, NULL);
}

PyObject *make_file_foldmap(PyObject *self, PyObject *args)
{
	PyObject *dmap, *spec_obj, *normcase_fallback;
	PyObject *file_foldmap = NULL;
	enum normcase_spec spec;
	PyObject *k, *v;
	dirstateItemObject *tuple;
	Py_ssize_t pos = 0;
	const char *table;

	if (!PyArg_ParseTuple(args, "O!O!O!:make_file_foldmap", &PyDict_Type,
	                      &dmap, &PyLong_Type, &spec_obj, &PyFunction_Type,
	                      &normcase_fallback)) {
		goto quit;
	}

	spec = (int)PyLong_AS_LONG(spec_obj);
	switch (spec) {
	case NORMCASE_LOWER:
		table = lowertable;
		break;
	case NORMCASE_UPPER:
		table = uppertable;
		break;
	case NORMCASE_OTHER:
		table = NULL;
		break;
	default:
		PyErr_SetString(PyExc_TypeError, "invalid normcasespec");
		goto quit;
	}

	/* Add some more entries to deal with additions outside this
	   function. */
	file_foldmap = _dict_new_presized((PyDict_Size(dmap) / 10) * 11);
	if (file_foldmap == NULL) {
		goto quit;
	}

	while (PyDict_Next(dmap, &pos, &k, &v)) {
		if (!dirstate_tuple_check(v)) {
			PyErr_SetString(PyExc_TypeError,
			                "expected a dirstate tuple");
			goto quit;
		}

		tuple = (dirstateItemObject *)v;
		if (tuple->flags | dirstate_flag_wc_tracked) {
			PyObject *normed;
			if (table != NULL) {
				normed = _asciitransform(k, table,
				                         normcase_fallback);
			} else {
				normed = PyObject_CallFunctionObjArgs(
				    normcase_fallback, k, NULL);
			}

			if (normed == NULL) {
				goto quit;
			}
			if (PyDict_SetItem(file_foldmap, normed, k) == -1) {
				Py_DECREF(normed);
				goto quit;
			}
			Py_DECREF(normed);
		}
	}
	return file_foldmap;
quit:
	Py_XDECREF(file_foldmap);
	return NULL;
}

/* calculate length of JSON-escaped string; returns -1 if unsupported */
static Py_ssize_t jsonescapelen(const char *buf, Py_ssize_t len, bool paranoid)
{
	Py_ssize_t i, esclen = 0;

	if (paranoid) {
		/* don't want to process multi-byte escapes in C */
		for (i = 0; i < len; i++) {
			char c = buf[i];
			if (c & 0x80) {
				PyErr_SetString(PyExc_ValueError,
				                "cannot process non-ascii str");
				return -1;
			}
			esclen += jsonparanoidlentable[(unsigned char)c];
			if (esclen < 0) {
				PyErr_SetString(PyExc_MemoryError,
				                "overflow in jsonescapelen");
				return -1;
			}
		}
	} else {
		for (i = 0; i < len; i++) {
			char c = buf[i];
			esclen += jsonlentable[(unsigned char)c];
			if (esclen < 0) {
				PyErr_SetString(PyExc_MemoryError,
				                "overflow in jsonescapelen");
				return -1;
			}
		}
	}

	return esclen;
}

/* map '\<c>' escape character */
static char jsonescapechar2(char c)
{
	switch (c) {
	case '\b':
		return 'b';
	case '\t':
		return 't';
	case '\n':
		return 'n';
	case '\f':
		return 'f';
	case '\r':
		return 'r';
	case '"':
		return '"';
	case '\\':
		return '\\';
	}
	return '\0'; /* should not happen */
}

/* convert 'origbuf' to JSON-escaped form 'escbuf'; 'origbuf' should only
   include characters mappable by json(paranoid)lentable */
static void encodejsonescape(char *escbuf, Py_ssize_t esclen,
                             const char *origbuf, Py_ssize_t origlen,
                             bool paranoid)
{
	const uint8_t *lentable =
	    (paranoid) ? jsonparanoidlentable : jsonlentable;
	Py_ssize_t i, j;

	for (i = 0, j = 0; i < origlen; i++) {
		char c = origbuf[i];
		uint8_t l = lentable[(unsigned char)c];
		assert(j + l <= esclen);
		switch (l) {
		case 1:
			escbuf[j] = c;
			break;
		case 2:
			escbuf[j] = '\\';
			escbuf[j + 1] = jsonescapechar2(c);
			break;
		case 6:
			memcpy(escbuf + j, "\\u00", 4);
			escbuf[j + 4] = hexchartable[(unsigned char)c >> 4];
			escbuf[j + 5] = hexchartable[(unsigned char)c & 0xf];
			break;
		}
		j += l;
	}
}

PyObject *jsonescapeu8fast(PyObject *self, PyObject *args)
{
	PyObject *origstr, *escstr;
	const char *origbuf;
	Py_ssize_t origlen, esclen;
	int paranoid;
	if (!PyArg_ParseTuple(args, "O!i:jsonescapeu8fast", &PyBytes_Type,
	                      &origstr, &paranoid)) {
		return NULL;
	}

	origbuf = PyBytes_AS_STRING(origstr);
	origlen = PyBytes_GET_SIZE(origstr);
	esclen = jsonescapelen(origbuf, origlen, paranoid);
	if (esclen < 0) {
		return NULL; /* unsupported char found or overflow */
	}
	if (origlen == esclen) {
		Py_INCREF(origstr);
		return origstr;
	}

	escstr = PyBytes_FromStringAndSize(NULL, esclen);
	if (!escstr) {
		return NULL;
	}
	encodejsonescape(PyBytes_AS_STRING(escstr), esclen, origbuf, origlen,
	                 paranoid);

	return escstr;
}