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-rw-r--r--builtin-apply.c206
1 files changed, 141 insertions, 65 deletions
diff --git a/builtin-apply.c b/builtin-apply.c
index 267aab0..4573c9a 100644
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -109,6 +109,13 @@ static int max_change, max_len;
*/
static int linenr = 1;
+/*
+ * This represents one "hunk" from a patch, starting with
+ * "@@ -oldpos,oldlines +newpos,newlines @@" marker. The
+ * patch text is pointed at by patch, and its byte length
+ * is stored in size. leading and trailing are the number
+ * of context lines.
+ */
struct fragment {
unsigned long leading, trailing;
unsigned long oldpos, oldlines;
@@ -118,12 +125,19 @@ struct fragment {
struct fragment *next;
};
+/*
+ * When dealing with a binary patch, we reuse "leading" field
+ * to store the type of the binary hunk, either deflated "delta"
+ * or deflated "literal".
+ */
+#define binary_patch_method leading
+#define BINARY_DELTA_DEFLATED 1
+#define BINARY_LITERAL_DEFLATED 2
+
struct patch {
char *new_name, *old_name, *def_name;
unsigned int old_mode, new_mode;
int is_rename, is_copy, is_new, is_delete, is_binary;
-#define BINARY_DELTA_DEFLATED 1
-#define BINARY_LITERAL_DEFLATED 2
unsigned long deflate_origlen;
int lines_added, lines_deleted;
int score;
@@ -979,43 +993,70 @@ static inline int metadata_changes(struct patch *patch)
patch->old_mode != patch->new_mode);
}
-static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
+static char *inflate_it(const void *data, unsigned long size,
+ unsigned long inflated_size)
{
- /* We have read "GIT binary patch\n"; what follows is a line
- * that says the patch method (currently, either "deflated
- * literal" or "deflated delta") and the length of data before
- * deflating; a sequence of 'length-byte' followed by base-85
- * encoded data follows.
+ z_stream stream;
+ void *out;
+ int st;
+
+ memset(&stream, 0, sizeof(stream));
+
+ stream.next_in = (unsigned char *)data;
+ stream.avail_in = size;
+ stream.next_out = out = xmalloc(inflated_size);
+ stream.avail_out = inflated_size;
+ inflateInit(&stream);
+ st = inflate(&stream, Z_FINISH);
+ if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
+ free(out);
+ return NULL;
+ }
+ return out;
+}
+
+static struct fragment *parse_binary_hunk(char **buf_p,
+ unsigned long *sz_p,
+ int *status_p,
+ int *used_p)
+{
+ /* Expect a line that begins with binary patch method ("literal"
+ * or "delta"), followed by the length of data before deflating.
+ * a sequence of 'length-byte' followed by base-85 encoded data
+ * should follow, terminated by a newline.
*
* Each 5-byte sequence of base-85 encodes up to 4 bytes,
* and we would limit the patch line to 66 characters,
* so one line can fit up to 13 groups that would decode
* to 52 bytes max. The length byte 'A'-'Z' corresponds
* to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
- * The end of binary is signaled with an empty line.
*/
int llen, used;
- struct fragment *fragment;
+ unsigned long size = *sz_p;
+ char *buffer = *buf_p;
+ int patch_method;
+ unsigned long origlen;
char *data = NULL;
+ int hunk_size = 0;
+ struct fragment *frag;
- patch->fragments = fragment = xcalloc(1, sizeof(*fragment));
-
- /* Grab the type of patch */
llen = linelen(buffer, size);
used = llen;
- linenr++;
+
+ *status_p = 0;
if (!strncmp(buffer, "delta ", 6)) {
- patch->is_binary = BINARY_DELTA_DEFLATED;
- patch->deflate_origlen = strtoul(buffer + 6, NULL, 10);
+ patch_method = BINARY_DELTA_DEFLATED;
+ origlen = strtoul(buffer + 6, NULL, 10);
}
else if (!strncmp(buffer, "literal ", 8)) {
- patch->is_binary = BINARY_LITERAL_DEFLATED;
- patch->deflate_origlen = strtoul(buffer + 8, NULL, 10);
+ patch_method = BINARY_LITERAL_DEFLATED;
+ origlen = strtoul(buffer + 8, NULL, 10);
}
else
- return error("unrecognized binary patch at line %d: %.*s",
- linenr-1, llen-1, buffer);
+ return NULL;
+
+ linenr++;
buffer += llen;
while (1) {
int byte_length, max_byte_length, newsize;
@@ -1044,21 +1085,79 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
if (max_byte_length < byte_length ||
byte_length <= max_byte_length - 4)
goto corrupt;
- newsize = fragment->size + byte_length;
+ newsize = hunk_size + byte_length;
data = xrealloc(data, newsize);
- if (decode_85(data + fragment->size,
- buffer + 1,
- byte_length))
+ if (decode_85(data + hunk_size, buffer + 1, byte_length))
goto corrupt;
- fragment->size = newsize;
+ hunk_size = newsize;
buffer += llen;
size -= llen;
}
- fragment->patch = data;
- return used;
+
+ frag = xcalloc(1, sizeof(*frag));
+ frag->patch = inflate_it(data, hunk_size, origlen);
+ if (!frag->patch)
+ goto corrupt;
+ free(data);
+ frag->size = origlen;
+ *buf_p = buffer;
+ *sz_p = size;
+ *used_p = used;
+ frag->binary_patch_method = patch_method;
+ return frag;
+
corrupt:
- return error("corrupt binary patch at line %d: %.*s",
- linenr-1, llen-1, buffer);
+ if (data)
+ free(data);
+ *status_p = -1;
+ error("corrupt binary patch at line %d: %.*s",
+ linenr-1, llen-1, buffer);
+ return NULL;
+}
+
+static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
+{
+ /* We have read "GIT binary patch\n"; what follows is a line
+ * that says the patch method (currently, either "literal" or
+ * "delta") and the length of data before deflating; a
+ * sequence of 'length-byte' followed by base-85 encoded data
+ * follows.
+ *
+ * When a binary patch is reversible, there is another binary
+ * hunk in the same format, starting with patch method (either
+ * "literal" or "delta") with the length of data, and a sequence
+ * of length-byte + base-85 encoded data, terminated with another
+ * empty line. This data, when applied to the postimage, produces
+ * the preimage.
+ */
+ struct fragment *forward;
+ struct fragment *reverse;
+ int status;
+ int used, used_1;
+
+ forward = parse_binary_hunk(&buffer, &size, &status, &used);
+ if (!forward && !status)
+ /* there has to be one hunk (forward hunk) */
+ return error("unrecognized binary patch at line %d", linenr-1);
+ if (status)
+ /* otherwise we already gave an error message */
+ return status;
+
+ reverse = parse_binary_hunk(&buffer, &size, &status, &used_1);
+ if (reverse)
+ used += used_1;
+ else if (status) {
+ /* not having reverse hunk is not an error, but having
+ * a corrupt reverse hunk is.
+ */
+ free((void*) forward->patch);
+ free(forward);
+ return status;
+ }
+ forward->next = reverse;
+ patch->fragments = forward;
+ patch->is_binary = 1;
+ return used;
}
static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
@@ -1505,28 +1604,6 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag, i
return offset;
}
-static char *inflate_it(const void *data, unsigned long size,
- unsigned long inflated_size)
-{
- z_stream stream;
- void *out;
- int st;
-
- memset(&stream, 0, sizeof(stream));
-
- stream.next_in = (unsigned char *)data;
- stream.avail_in = size;
- stream.next_out = out = xmalloc(inflated_size);
- stream.avail_out = inflated_size;
- inflateInit(&stream);
- st = inflate(&stream, Z_FINISH);
- if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
- free(out);
- return NULL;
- }
- return out;
-}
-
static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
{
unsigned long dst_size;
@@ -1534,30 +1611,29 @@ static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
void *data;
void *result;
- /* Binary patch is irreversible */
- if (apply_in_reverse)
- return error("cannot reverse-apply a binary patch to '%s'",
- patch->new_name
- ? patch->new_name : patch->old_name);
-
- data = inflate_it(fragment->patch, fragment->size,
- patch->deflate_origlen);
- if (!data)
- return error("corrupt patch data");
- switch (patch->is_binary) {
+ /* Binary patch is irreversible without the optional second hunk */
+ if (apply_in_reverse) {
+ if (!fragment->next)
+ return error("cannot reverse-apply a binary patch "
+ "without the reverse hunk to '%s'",
+ patch->new_name
+ ? patch->new_name : patch->old_name);
+ fragment = fragment;
+ }
+ data = (void*) fragment->patch;
+ switch (fragment->binary_patch_method) {
case BINARY_DELTA_DEFLATED:
result = patch_delta(desc->buffer, desc->size,
data,
- patch->deflate_origlen,
+ fragment->size,
&dst_size);
free(desc->buffer);
desc->buffer = result;
- free(data);
break;
case BINARY_LITERAL_DEFLATED:
free(desc->buffer);
desc->buffer = data;
- dst_size = patch->deflate_origlen;
+ dst_size = fragment->size;
break;
}
if (!desc->buffer)