mercurial/base85.c

largefiles: synchronize lfdirstate with dirstate after automated committing

Before this patch, after successful "hg rebase" of the revision
removing largefiles, "hg status" may still show ""R" for such
largefiles unexpectedly.

"lfilesrepo.commit" executes the special code path for automated
committing while rebase/transplant, and lfdirstate entries for removed
files aren't updated in this code path, even after successful
committing.

Then, "R" entries still existing in lfdirstate cause unexpected "hg
status" output.

This patch synchronizes lfdirstate with dirstate after automated
committing.

This patch passes False as "normallookup" to "synclfdirstate", because
modified files in "files()" of the recent (= just committed) context
should be "normal"-ed.

This is a temporary way to fix with less changes. For fundamental
resolution of this kind of problems in the future, lfdirstate should
be updated with dirstate simultaneously. Hooking "markcommitted" of
ctx in "localrepository.commitctx" may achieve this.

This problem occurs, only when (1) the parent of the working directory
is rebased and (2) it removes largefiles, because:

  - if the parent of the working directory isn't rebased, returning to
    the initial revision (= update) after rebase hides this problem

  - files added on "other" branch (= rebase target) are treated not as
    "added" but as "modified" (= "normal" status and "unset"
    timestamp) at merging

This patch tests also the status of added largefile, but it is only
for avoiding regression.

In addition to conditions above, "hg status" must not take existing
files to reproduce this problem, because existing files make
"match._files" not empty in "lfilesrepo.status" code path below:

    def sfindirstate(f):
        sf = lfutil.standin(f)
        dirstate = self.dirstate
        return sf in dirstate or sf in dirstate.dirs()

    match._files = [f for f in match._files
                    if sfindirstate(f)]

Not empty "match._files" prevents "status" on lfdirstate from
returning the result containing problematic "R" files.

This is reason why "large1" (removed) and "largeX" (added) are checked
separately in this patch.

Problematic code path in "lfilesrepo.commit" is used also by "hg
transplant", but this problem doesn't occur at "hg transplant",
because invocation of "updatelfiles" after transplant-ing in
"overridetransplant" causes cleaning lfdirstate up.

This patch tests also "hg transplant" as same as "hg rebase", but it
is only for avoiding regression.

/*
 base85 codec

 Copyright 2006 Brendan Cully <[e-mail]>

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

 Largely based on git's implementation
*/

#define PY_SSIZE_T_CLEAN
#include <Python.h>

#include "util.h"

static const char b85chars[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
	"abcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
static char b85dec[256];

static void
b85prep(void)
{
	int i;

	memset(b85dec, 0, sizeof(b85dec));
	for (i = 0; i < sizeof(b85chars); i++)
		b85dec[(int)(b85chars[i])] = i + 1;
}

static PyObject *
b85encode(PyObject *self, PyObject *args)
{
	const unsigned char *text;
	PyObject *out;
	char *dst;
	Py_ssize_t len, olen, i;
	unsigned int acc, val, ch;
	int pad = 0;

	if (!PyArg_ParseTuple(args, "s#|i", &text, &len, &pad))
		return NULL;

	if (pad)
		olen = ((len + 3) / 4 * 5) - 3;
	else {
		olen = len % 4;
		if (olen)
			olen++;
		olen += len / 4 * 5;
	}
	if (!(out = PyBytes_FromStringAndSize(NULL, olen + 3)))
		return NULL;

	dst = PyBytes_AsString(out);

	while (len) {
		acc = 0;
		for (i = 24; i >= 0; i -= 8) {
			ch = *text++;
			acc |= ch << i;
			if (--len == 0)
				break;
		}
		for (i = 4; i >= 0; i--) {
			val = acc % 85;
			acc /= 85;
			dst[i] = b85chars[val];
		}
		dst += 5;
	}

	if (!pad)
		_PyBytes_Resize(&out, olen);

	return out;
}

static PyObject *
b85decode(PyObject *self, PyObject *args)
{
	PyObject *out;
	const char *text;
	char *dst;
	Py_ssize_t len, i, j, olen, cap;
	int c;
	unsigned int acc;

	if (!PyArg_ParseTuple(args, "s#", &text, &len))
		return NULL;

	olen = len / 5 * 4;
	i = len % 5;
	if (i)
		olen += i - 1;
	if (!(out = PyBytes_FromStringAndSize(NULL, olen)))
		return NULL;

	dst = PyBytes_AsString(out);

	i = 0;
	while (i < len)
	{
		acc = 0;
		cap = len - i - 1;
		if (cap > 4)
			cap = 4;
		for (j = 0; j < cap; i++, j++)
		{
			c = b85dec[(int)*text++] - 1;
			if (c < 0)
				return PyErr_Format(
					PyExc_ValueError,
					"bad base85 character at position %d",
					(int)i);
			acc = acc * 85 + c;
		}
		if (i++ < len)
		{
			c = b85dec[(int)*text++] - 1;
			if (c < 0)
				return PyErr_Format(
					PyExc_ValueError,
					"bad base85 character at position %d",
					(int)i);
			/* overflow detection: 0xffffffff == "|NsC0",
			 * "|NsC" == 0x03030303 */
			if (acc > 0x03030303 || (acc *= 85) > 0xffffffff - c)
				return PyErr_Format(
					PyExc_ValueError,
					"bad base85 sequence at position %d",
					(int)i);
			acc += c;
		}

		cap = olen < 4 ? olen : 4;
		olen -= cap;
		for (j = 0; j < 4 - cap; j++)
			acc *= 85;
		if (cap && cap < 4)
			acc += 0xffffff >> (cap - 1) * 8;
		for (j = 0; j < cap; j++)
		{
			acc = (acc << 8) | (acc >> 24);
			*dst++ = acc;
		}
	}

	return out;
}

static char base85_doc[] = "Base85 Data Encoding";

static PyMethodDef methods[] = {
	{"b85encode", b85encode, METH_VARARGS,
	 "Encode text in base85.\n\n"
	 "If the second parameter is true, pad the result to a multiple of "
	 "five characters.\n"},
	{"b85decode", b85decode, METH_VARARGS, "Decode base85 text.\n"},
	{NULL, NULL}
};

#ifdef IS_PY3K
static struct PyModuleDef base85_module = {
	PyModuleDef_HEAD_INIT,
	"base85",
	base85_doc,
	-1,
	methods
};

PyMODINIT_FUNC PyInit_base85(void)
{
	b85prep();

	return PyModule_Create(&base85_module);
}
#else
PyMODINIT_FUNC initbase85(void)
{
	Py_InitModule3("base85", methods, base85_doc);

	b85prep();
}
#endif