/*
* Copyright (C) the libgit2 contributors. All rights reserved.
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#include <assert.h>
#include "git2/patch.h"
#include "git2/filter.h"
#include "array.h"
#include "patch.h"
#include "fileops.h"
#include "apply.h"
#include "delta.h"
#include "zstream.h"
#define apply_err(...) \
( giterr_set(GITERR_PATCH, __VA_ARGS__), -1 )
typedef struct {
/* The lines that we allocate ourself are allocated out of the pool.
* (Lines may have been allocated out of the diff.)
*/
git_pool pool;
git_vector lines;
} patch_image;
static void patch_line_init(
git_diff_line *out,
const char *in,
size_t in_len,
size_t in_offset)
{
out->content = in;
out->content_len = in_len;
out->content_offset = in_offset;
}
#define PATCH_IMAGE_INIT { GIT_POOL_INIT, GIT_VECTOR_INIT }
static int patch_image_init_fromstr(
patch_image *out, const char *in, size_t in_len)
{
git_diff_line *line;
const char *start, *end;
memset(out, 0x0, sizeof(patch_image));
git_pool_init(&out->pool, sizeof(git_diff_line));
for (start = in; start < in + in_len; start = end) {
end = memchr(start, '\n', in_len);
if (end == NULL)
end = in + in_len;
else if (end < in + in_len)
end++;
line = git_pool_mallocz(&out->pool, 1);
GITERR_CHECK_ALLOC(line);
if (git_vector_insert(&out->lines, line) < 0)
return -1;
patch_line_init(line, start, (end - start), (start - in));
}
return 0;
}
static void patch_image_free(patch_image *image)
{
if (image == NULL)
return;
git_pool_clear(&image->pool);
git_vector_free(&image->lines);
}
static bool match_hunk(
patch_image *image,
patch_image *preimage,
size_t linenum)
{
bool match = 0;
size_t i;
/* Ensure this hunk is within the image boundaries. */
if (git_vector_length(&preimage->lines) + linenum >
git_vector_length(&image->lines))
return 0;
match = 1;
/* Check exact match. */
for (i = 0; i < git_vector_length(&preimage->lines); i++) {
git_diff_line *preimage_line = git_vector_get(&preimage->lines, i);
git_diff_line *image_line = git_vector_get(&image->lines, linenum + i);
if (preimage_line->content_len != image_line->content_len ||
memcmp(preimage_line->content, image_line->content, image_line->content_len) != 0) {
match = 0;
break;
}
}
return match;
}
static bool find_hunk_linenum(
size_t *out,
patch_image *image,
patch_image *preimage,
size_t linenum)
{
size_t max = git_vector_length(&image->lines);
bool match;
if (linenum > max)
linenum = max;
match = match_hunk(image, preimage, linenum);
*out = linenum;
return match;
}
static int update_hunk(
patch_image *image,
unsigned int linenum,
patch_image *preimage,
patch_image *postimage)
{
size_t postlen = git_vector_length(&postimage->lines);
size_t prelen = git_vector_length(&preimage->lines);
size_t i;
int error = 0;
if (postlen > prelen)
error = git_vector_insert_null(
&image->lines, linenum, (postlen - prelen));
else if (prelen > postlen)
error = git_vector_remove_range(
&image->lines, linenum, (prelen - postlen));
if (error) {
giterr_set_oom();
return -1;
}
for (i = 0; i < git_vector_length(&postimage->lines); i++) {
image->lines.contents[linenum + i] =
git_vector_get(&postimage->lines, i);
}
return 0;
}
static int apply_hunk(
patch_image *image,
git_patch *patch,
git_patch_hunk *hunk)
{
patch_image preimage = PATCH_IMAGE_INIT, postimage = PATCH_IMAGE_INIT;
size_t line_num, i;
int error = 0;
for (i = 0; i < hunk->line_count; i++) {
size_t linenum = hunk->line_start + i;
git_diff_line *line = git_array_get(patch->lines, linenum);
if (!line) {
error = apply_err("preimage does not contain line %"PRIuZ, linenum);
goto done;
}
if (line->origin == GIT_DIFF_LINE_CONTEXT ||
line->origin == GIT_DIFF_LINE_DELETION) {
if ((error = git_vector_insert(&preimage.lines, line)) < 0)
goto done;
}
if (line->origin == GIT_DIFF_LINE_CONTEXT ||
line->origin == GIT_DIFF_LINE_ADDITION) {
if ((error = git_vector_insert(&postimage.lines, line)) < 0)
goto done;
}
}
line_num = hunk->hunk.new_start ? hunk->hunk.new_start - 1 : 0;
if (!find_hunk_linenum(&line_num, image, &preimage, line_num)) {
error = apply_err("hunk at line %d did not apply",
hunk->hunk.new_start);
goto done;
}
error = update_hunk(image, line_num, &preimage, &postimage);
done:
patch_image_free(&preimage);
patch_image_free(&postimage);
return error;
}
static int apply_hunks(
git_buf *out,
const char *source,
size_t source_len,
git_patch *patch)
{
git_patch_hunk *hunk;
git_diff_line *line;
patch_image image;
size_t i;
int error = 0;
if ((error = patch_image_init_fromstr(&image, source, source_len)) < 0)
goto done;
git_array_foreach(patch->hunks, i, hunk) {
if ((error = apply_hunk(&image, patch, hunk)) < 0)
goto done;
}
git_vector_foreach(&image.lines, i, line)
git_buf_put(out, line->content, line->content_len);
done:
patch_image_free(&image);
return error;
}
static int apply_binary_delta(
git_buf *out,
const char *source,
size_t source_len,
git_diff_binary_file *binary_file)
{
git_buf inflated = GIT_BUF_INIT;
int error = 0;
/* no diff means identical contents */
if (binary_file->datalen == 0)
return git_buf_put(out, source, source_len);
error = git_zstream_inflatebuf(&inflated,
binary_file->data, binary_file->datalen);
if (!error && inflated.size != binary_file->inflatedlen) {
error = apply_err("inflated delta does not match expected length");
git_buf_free(out);
}
if (error < 0)
goto done;
if (binary_file->type == GIT_DIFF_BINARY_DELTA) {
void *data;
size_t data_len;
error = git_delta_apply(&data, &data_len, (void *)source, source_len,
(void *)inflated.ptr, inflated.size);
out->ptr = data;
out->size = data_len;
out->asize = data_len;
}
else if (binary_file->type == GIT_DIFF_BINARY_LITERAL) {
git_buf_swap(out, &inflated);
}
else {
error = apply_err("unknown binary delta type");
goto done;
}
done:
git_buf_free(&inflated);
return error;
}
static int apply_binary(
git_buf *out,
const char *source,
size_t source_len,
git_patch *patch)
{
git_buf reverse = GIT_BUF_INIT;
int error = 0;
if (!patch->binary.contains_data) {
error = apply_err("patch does not contain binary data");
goto done;
}
if (!patch->binary.old_file.datalen && !patch->binary.new_file.datalen)
goto done;
/* first, apply the new_file delta to the given source */
if ((error = apply_binary_delta(out, source, source_len,
&patch->binary.new_file)) < 0)
goto done;
/* second, apply the old_file delta to sanity check the result */
if ((error = apply_binary_delta(&reverse, out->ptr, out->size,
&patch->binary.old_file)) < 0)
goto done;
if (source_len != reverse.size ||
memcmp(source, reverse.ptr, source_len) != 0) {
error = apply_err("binary patch did not apply cleanly");
goto done;
}
done:
if (error < 0)
git_buf_free(out);
git_buf_free(&reverse);
return error;
}
int git_apply__patch(
git_buf *contents_out,
char **filename_out,
unsigned int *mode_out,
const char *source,
size_t source_len,
git_patch *patch)
{
char *filename = NULL;
unsigned int mode = 0;
int error = 0;
assert(contents_out && filename_out && mode_out && (source || !source_len) && patch);
*filename_out = NULL;
*mode_out = 0;
if (patch->delta->status != GIT_DELTA_DELETED) {
const git_diff_file *newfile = &patch->delta->new_file;
filename = git__strdup(newfile->path);
mode = newfile->mode ?
newfile->mode : GIT_FILEMODE_BLOB;
}
if (patch->delta->flags & GIT_DIFF_FLAG_BINARY)
error = apply_binary(contents_out, source, source_len, patch);
else if (patch->hunks.size)
error = apply_hunks(contents_out, source, source_len, patch);
else
error = git_buf_put(contents_out, source, source_len);
if (error)
goto done;
if (patch->delta->status == GIT_DELTA_DELETED &&
git_buf_len(contents_out) > 0) {
error = apply_err("removal patch leaves file contents");
goto done;
}
*filename_out = filename;
*mode_out = mode;
done:
if (error < 0)
git__free(filename);
return error;
}