busybox/editors/patch.c

/* Adapted from toybox's patch. */

/* vi: set sw=4 ts=4:
 *
 * patch.c - Apply a "universal" diff.
 *
 * Copyright 2007 Rob Landley <rob@landley.net>
 *
 * see http://www.opengroup.org/onlinepubs/009695399/utilities/patch.html
 * (But only does -u, because who still cares about "ed"?)
 *
 * TODO:
 * -b backup
 * -l treat all whitespace as a single space
 * -d chdir first
 * -D define wrap #ifdef and #ifndef around changes
 * -o outfile output here instead of in place
 * -r rejectfile write rejected hunks to this file
 *
 * -E remove empty files --remove-empty-files
 * -f force (no questions asked)
 * -F fuzz (number, default 2)
 * [file] which file to patch

USE_PATCH(NEWTOY(patch, USE_TOYBOX_DEBUG("x")"up#i:R", TOYFLAG_USR|TOYFLAG_BIN))

config PATCH
	bool "patch"
	default y
	help
	  usage: patch [-i file] [-p depth] [-Ru]

	  Apply a unified diff to one or more files.

	  -i	Input file (defaults=stdin)
	  -p	number of '/' to strip from start of file paths (default=all)
	  -R	Reverse patch.
	  -u	Ignored (only handles "unified" diffs)

	  This version of patch only handles unified diffs, and only modifies
	  a file when all all hunks to that file apply.  Patch prints failed
	  hunks to stderr, and exits with nonzero status if any hunks fail.

	  A file compared against /dev/null (or with a date <= the epoch) is
	  created/deleted as appropriate.
*/
#include "libbb.h"

struct double_list {
	struct double_list *next;
	struct double_list *prev;
	char *data;
};

// Return the first item from the list, advancing the list (which must be called
// as &list)
static
void *TOY_llist_pop(void *list)
{
	// I'd use a void ** for the argument, and even accept the typecast in all
	// callers as documentation you need the &, except the stupid compiler
	// would then scream about type-punned pointers.  Screw it.
	void **llist = (void **)list;
	void **next = (void **)*llist;
	*llist = *next;

	return (void *)next;
}

// Free all the elements of a linked list
// if freeit!=NULL call freeit() on each element before freeing it.
static
void TOY_llist_free(void *list, void (*freeit)(void *data))
{
	while (list) {
		void *pop = TOY_llist_pop(&list);
		if (freeit) freeit(pop);
		else free(pop);

		// End doubly linked list too.
		if (list==pop) break;
	}
}
//Override bbox's names
#define llist_pop TOY_llist_pop
#define llist_free TOY_llist_free

// Add an entry to the end off a doubly linked list
static
struct double_list *dlist_add(struct double_list **list, char *data)
{
	struct double_list *line = xmalloc(sizeof(struct double_list));

	line->data = data;
	if (*list) {
		line->next = *list;
		line->prev = (*list)->prev;
		(*list)->prev->next = line;
		(*list)->prev = line;
	} else *list = line->next = line->prev = line;

	return line;
}

// Ensure entire path exists.
// If mode != -1 set permissions on newly created dirs.
// Requires that path string be writable (for temporary null terminators).
static
void xmkpath(char *path, int mode)
{
	char *p, old;
	mode_t mask;
	int rc;
	struct stat st;

	for (p = path; ; p++) {
		if (!*p || *p == '/') {
			old = *p;
			*p = rc = 0;
			if (stat(path, &st) || !S_ISDIR(st.st_mode)) {
				if (mode != -1) {
					mask = umask(0);
					rc = mkdir(path, mode);
					umask(mask);
				} else rc = mkdir(path, 0777);
			}
			*p = old;
			if(rc) bb_perror_msg_and_die("mkpath '%s'", path);
		}
		if (!*p) break;
	}
}

// Slow, but small.
static
char *get_rawline(int fd, long *plen, char end)
{
	char c, *buf = NULL;
	long len = 0;

	for (;;) {
		if (1>read(fd, &c, 1)) break;
		if (!(len & 63)) buf=xrealloc(buf, len+65);
		if ((buf[len++]=c) == end) break;
	}
	if (buf) buf[len]=0;
	if (plen) *plen = len;

	return buf;
}

static
char *get_line(int fd)
{
	long len;
	char *buf = get_rawline(fd, &len, '\n');

	if (buf && buf[--len]=='\n') buf[len]=0;

	return buf;
}

// Copy the rest of in to out and close both files.
static
void xsendfile(int in, int out)
{
	long len;
	char buf[4096];

	if (in<0) return;
	for (;;) {
		len = safe_read(in, buf, 4096);
		if (len<1) break;
		xwrite(out, buf, len);
	}
}

// Copy the rest of the data and replace the original with the copy.
static
void replace_tempfile(int fdin, int fdout, char **tempname)
{
	char *temp = xstrdup(*tempname);

	temp[strlen(temp)-6]=0;
	if (fdin != -1) {
		xsendfile(fdin, fdout);
		xclose(fdin);
	}
	xclose(fdout);
	rename(*tempname, temp);
	free(*tempname);
	free(temp);
	*tempname = NULL;
}

// Open a temporary file to copy an existing file into.
static
int copy_tempfile(int fdin, char *name, char **tempname)
{
	struct stat statbuf;
	int fd;

	*tempname = xasprintf("%sXXXXXX", name);
	fd = mkstemp(*tempname);
	if(-1 == fd) bb_perror_msg_and_die("no temp file");

	// Set permissions of output file
	fstat(fdin, &statbuf);
	fchmod(fd, statbuf.st_mode);

	return fd;
}

// Abort the copy and delete the temporary file.
static
void delete_tempfile(int fdin, int fdout, char **tempname)
{
	close(fdin);
	close(fdout);
	unlink(*tempname);
	free(*tempname);
	*tempname = NULL;
}


struct globals {
	char *infile;
	long prefix;

	struct double_list *current_hunk;
	long oldline, oldlen, newline, newlen;
	long linenum;
	int context, state, filein, fileout, filepatch, hunknum;
	char *tempname;

	// was toys.foo:
	int exitval;
};
#define TT (*ptr_to_globals)
#define INIT_TT() do { \
	SET_PTR_TO_GLOBALS(xzalloc(sizeof(TT))); \
} while (0)


#define FLAG_STR "Rup:i:Nx"
/* FLAG_REVERSE must be == 1! Code uses this fact. */
#define FLAG_REVERSE (1 << 0)
#define FLAG_u       (1 << 1)
#define FLAG_PATHLEN (1 << 2)
#define FLAG_INPUT   (1 << 3)
#define FLAG_IGNORE  (1 << 4)
//non-standard:
#define FLAG_DEBUG   (1 << 5)

// Dispose of a line of input, either by writing it out or discarding it.

// state < 2: just free
// state = 2: write whole line to stderr
// state = 3: write whole line to fileout
// state > 3: write line+1 to fileout when *line != state

#define PATCH_DEBUG (option_mask32 & FLAG_DEBUG)

static void do_line(void *data)
{
	struct double_list *dlist = (struct double_list *)data;

	if (TT.state>1 && *dlist->data != TT.state)
		fdprintf(TT.state == 2 ? 2 : TT.fileout,
			"%s\n", dlist->data+(TT.state>3 ? 1 : 0));

	if (PATCH_DEBUG) fdprintf(2, "DO %d: %s\n", TT.state, dlist->data);

	free(dlist->data);
	free(data);
}

static void finish_oldfile(void)
{
	if (TT.tempname) replace_tempfile(TT.filein, TT.fileout, &TT.tempname);
	TT.fileout = TT.filein = -1;
}

static void fail_hunk(void)
{
	if (!TT.current_hunk) return;
	TT.current_hunk->prev->next = 0;

	fdprintf(2, "Hunk %d FAILED %ld/%ld.\n", TT.hunknum, TT.oldline, TT.newline);
	TT.exitval = 1;

	// If we got to this point, we've seeked to the end.  Discard changes to
	// this file and advance to next file.

	TT.state = 2;
	llist_free(TT.current_hunk, do_line);
	TT.current_hunk = NULL;
	delete_tempfile(TT.filein, TT.fileout, &TT.tempname);
	TT.state = 0;
}

// Given a hunk of a unified diff, make the appropriate change to the file.
// This does not use the location information, but instead treats a hunk
// as a sort of regex.  Copies data from input to output until it finds
// the change to be made, then outputs the changed data and returns.
// (Finding EOF first is an error.)  This is a single pass operation, so
// multiple hunks must occur in order in the file.

static int apply_one_hunk(void)
{
	struct double_list *plist, *buf = NULL, *check;
	int matcheof = 0, reverse = option_mask32 & FLAG_REVERSE, backwarn = 0;
	/* Do we try "dummy" revert to check whether
	 * to silently skip this hunk? Used to implement -N.
	 */
	int dummy_revert = 0;

	// Break doubly linked list so we can use singly linked traversal function.
	TT.current_hunk->prev->next = NULL;

	// Match EOF if there aren't as many ending context lines as beginning
	for (plist = TT.current_hunk; plist; plist = plist->next) {
		if (plist->data[0]==' ') matcheof++;
		else matcheof = 0;
		if (PATCH_DEBUG) fdprintf(2, "HUNK:%s\n", plist->data);
	}
	matcheof = matcheof < TT.context;

	if (PATCH_DEBUG) fdprintf(2,"MATCHEOF=%c\n", matcheof ? 'Y' : 'N');

	// Loop through input data searching for this hunk.  Match all context
	// lines and all lines to be removed until we've found the end of a
	// complete hunk.
	plist = TT.current_hunk;
	buf = NULL;
	if (TT.context) for (;;) {
		char *data = get_line(TT.filein);

		TT.linenum++;

		// Figure out which line of hunk to compare with next.  (Skip lines
		// of the hunk we'd be adding.)
		while (plist && *plist->data == "+-"[reverse]) {
			if (data && !strcmp(data, plist->data+1)) {
				if (!backwarn) {
					backwarn++;
					if (option_mask32 & FLAG_IGNORE) {
						dummy_revert = 1;
						reverse ^= 1;
						continue;
					}
					fdprintf(2,"Possibly reversed hunk %d at %ld\n",
						TT.hunknum, TT.linenum);
				}
			}
			plist = plist->next;
		}

		// Is this EOF?
		if (!data) {
			if (PATCH_DEBUG) fdprintf(2, "INEOF\n");

			// Does this hunk need to match EOF?
			if (!plist && matcheof) break;

			// File ended before we found a place for this hunk.
			fail_hunk();
			goto done;
		} else if (PATCH_DEBUG) fdprintf(2, "IN: %s\n", data);
		check = dlist_add(&buf, data);

		// Compare this line with next expected line of hunk.
		// todo: teach the strcmp() to ignore whitespace.

		// A match can fail because the next line doesn't match, or because
		// we hit the end of a hunk that needed EOF, and this isn't EOF.

		// If match failed, flush first line of buffered data and
		// recheck buffered data for a new match until we find one or run
		// out of buffer.

		for (;;) {
			if (!plist || strcmp(check->data, plist->data+1)) {
				// Match failed.  Write out first line of buffered data and
				// recheck remaining buffered data for a new match.

				if (PATCH_DEBUG)
					fdprintf(2, "NOT: %s\n", plist->data);

				TT.state = 3;
				check = llist_pop(&buf);
				check->prev->next = buf;
				buf->prev = check->prev;
				do_line(check);
				plist = TT.current_hunk;

				// If we've reached the end of the buffer without confirming a
				// match, read more lines.
				if (check==buf) {
					buf = 0;
					break;
				}
				check = buf;
			} else {
				if (PATCH_DEBUG)
					fdprintf(2, "MAYBE: %s\n", plist->data);
				// This line matches.  Advance plist, detect successful match.
				plist = plist->next;
				if (!plist && !matcheof) goto out;
				check = check->next;
				if (check == buf) break;
			}
		}
	}
out:
	// We have a match.  Emit changed data.
	TT.state = "-+"[reverse ^ dummy_revert];
	llist_free(TT.current_hunk, do_line);
	TT.current_hunk = NULL;
	TT.state = 1;
done:
	if (buf) {
		buf->prev->next = NULL;
		llist_free(buf, do_line);
	}

	return TT.state;
}

// Read a patch file and find hunks, opening/creating/deleting files.
// Call apply_one_hunk() on each hunk.

// state 0: Not in a hunk, look for +++.
// state 1: Found +++ file indicator, look for @@
// state 2: In hunk: counting initial context lines
// state 3: In hunk: getting body

int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int patch_main(int argc UNUSED_PARAM, char **argv)
{
	int opts;
	int reverse, state = 0;
	char *oldname = NULL, *newname = NULL;
	char *opt_p, *opt_i;

	INIT_TT();

	opts = getopt32(argv, FLAG_STR, &opt_p, &opt_i);
	argv += optind;
	reverse = opts & FLAG_REVERSE;
	TT.prefix = (opts & FLAG_PATHLEN) ? xatoi(opt_p) : 0; // can be negative!
	TT.filein = TT.fileout = -1;
	if (opts & FLAG_INPUT) {
		TT.filepatch = xopen_stdin(opt_i);
	} else {
		if (argv[0] && argv[1]) {
			TT.filepatch = xopen_stdin(argv[1]);
		}
	}
	if (argv[0]) {
		oldname = xstrdup(argv[0]);
		newname = xstrdup(argv[0]);
	}

	// Loop through the lines in the patch
	for(;;) {
		char *patchline;

		patchline = get_line(TT.filepatch);
		if (!patchline) break;

		// Other versions of patch accept damaged patches,
		// so we need to also.
		if (!*patchline) {
			free(patchline);
			patchline = xstrdup(" ");
		}

		// Are we assembling a hunk?
		if (state >= 2) {
			if (*patchline==' ' || *patchline=='+' || *patchline=='-') {
				dlist_add(&TT.current_hunk, patchline);

				if (*patchline != '+') TT.oldlen--;
				if (*patchline != '-') TT.newlen--;

				// Context line?
				if (*patchline==' ' && state==2) TT.context++;
				else state=3;

				// If we've consumed all expected hunk lines, apply the hunk.

				if (!TT.oldlen && !TT.newlen) state = apply_one_hunk();
				continue;
			}
			fail_hunk();
			state = 0;
			continue;
		}

		// Open a new file?
		if (!strncmp("--- ", patchline, 4) || !strncmp("+++ ", patchline, 4)) {
			char *s, **name = reverse ? &newname : &oldname;
			int i;

			if (*patchline == '+') {
				name = reverse ? &oldname : &newname;
				state = 1;
			}

			finish_oldfile();

			if (!argv[0]) {
				free(*name);
				// Trim date from end of filename (if any).  We don't care.
				for (s = patchline+4; *s && *s!='\t'; s++)
					if (*s=='\\' && s[1]) s++;
				i = atoi(s);
				if (i>1900 && i<=1970)
					*name = xstrdup("/dev/null");
				else {
					*s = 0;
					*name = xstrdup(patchline+4);
				}
			}

			// We defer actually opening the file because svn produces broken
			// patches that don't signal they want to create a new file the
			// way the patch man page says, so you have to read the first hunk
			// and _guess_.

		// Start a new hunk?  Usually @@ -oldline,oldlen +newline,newlen @@
		// but a missing ,value means the value is 1.
		} else if (state == 1 && !strncmp("@@ -", patchline, 4)) {
			int i;
			char *s = patchline+4;

			// Read oldline[,oldlen] +newline[,newlen]

			TT.oldlen = TT.newlen = 1;
			TT.oldline = strtol(s, &s, 10);
			if (*s == ',') TT.oldlen=strtol(s+1, &s, 10);
			TT.newline = strtol(s+2, &s, 10);
			if (*s == ',') TT.newlen = strtol(s+1, &s, 10);

			TT.context = 0;
			state = 2;

			// If this is the first hunk, open the file.
			if (TT.filein == -1) {
				int oldsum, newsum, del = 0;
				char *name;

 				oldsum = TT.oldline + TT.oldlen;
				newsum = TT.newline + TT.newlen;

				name = reverse ? oldname : newname;

				// We're deleting oldname if new file is /dev/null (before -p)
				// or if new hunk is empty (zero context) after patching
				if (!strcmp(name, "/dev/null") || !(reverse ? oldsum : newsum))
				{
					name = reverse ? newname : oldname;
					del++;
				}

				// handle -p path truncation.
				for (i=0, s = name; *s;) {
					if ((option_mask32 & FLAG_PATHLEN) && TT.prefix == i) break;
					if (*(s++)=='/') {
						name = s;
						i++;
					}
				}

				if (del) {
					printf("removing %s\n", name);
					xunlink(name);
					state = 0;
				// If we've got a file to open, do so.
				} else if (!(option_mask32 & FLAG_PATHLEN) || i <= TT.prefix) {
					// If the old file was null, we're creating a new one.
					if (!strcmp(oldname, "/dev/null") || !oldsum) {
						printf("creating %s\n", name);
						s = strrchr(name, '/');
						if (s) {
							*s = 0;
							xmkpath(name, -1);
							*s = '/';
						}
						TT.filein = xopen3(name, O_CREAT|O_EXCL|O_RDWR, 0666);
					} else {
						printf("patching file %s\n", name);
						TT.filein = xopen(name, O_RDWR);
					}
					TT.fileout = copy_tempfile(TT.filein, name, &TT.tempname);
					TT.linenum = 0;
					TT.hunknum = 0;
				}
			}

			TT.hunknum++;

			continue;
		}

		// If we didn't continue above, discard this line.
		free(patchline);
	}

	finish_oldfile();

	if (ENABLE_FEATURE_CLEAN_UP) {
		close(TT.filepatch);
		free(oldname);
		free(newname);
	}

	return TT.exitval;
}
1	/* Adapted from toybox's patch. */
2
3	/* vi: set sw=4 ts=4:
4	*
5	* patch.c - Apply a "universal" diff.
6	*
7	* Copyright 2007 Rob Landley <rob@landley.net>
8	*
9	* see http://www.opengroup.org/onlinepubs/009695399/utilities/patch.html
10	* (But only does -u, because who still cares about "ed"?)
11	*
12	* TODO:
13	* -b backup
14	* -l treat all whitespace as a single space
15	* -d chdir first
16	* -D define wrap #ifdef and #ifndef around changes
17	* -o outfile output here instead of in place
18	* -r rejectfile write rejected hunks to this file
19	*
20	* -E remove empty files --remove-empty-files
21	* -f force (no questions asked)
22	* -F fuzz (number, default 2)
23	* [file] which file to patch
24
25	USE_PATCH(NEWTOY(patch, USE_TOYBOX_DEBUG("x")"up#i:R", TOYFLAG_USR\|TOYFLAG_BIN))
26
27	config PATCH
28	bool "patch"
29	default y
30	help
31	usage: patch [-i file] [-p depth] [-Ru]
32
33	Apply a unified diff to one or more files.
34
35	-i Input file (defaults=stdin)
36	-p number of '/' to strip from start of file paths (default=all)
37	-R Reverse patch.
38	-u Ignored (only handles "unified" diffs)
39
40	This version of patch only handles unified diffs, and only modifies
41	a file when all all hunks to that file apply. Patch prints failed
42	hunks to stderr, and exits with nonzero status if any hunks fail.
43
44	A file compared against /dev/null (or with a date <= the epoch) is
45	created/deleted as appropriate.
46	*/
47	#include "libbb.h"
48
49	struct double_list {
50	struct double_list *next;
51	struct double_list *prev;
52	char *data;
53	};
54
55	// Return the first item from the list, advancing the list (which must be called
56	// as &list)
57	static
58	void TOY_llist_pop(void list)
59	{
60	// I'd use a void ** for the argument, and even accept the typecast in all
61	// callers as documentation you need the &, except the stupid compiler
62	// would then scream about type-punned pointers. Screw it.
63	void llist = (void )list;
64	void next = (void )*llist;
65	llist = next;
66
67	return (void *)next;
68	}
69
70	// Free all the elements of a linked list
71	// if freeit!=NULL call freeit() on each element before freeing it.
72	static
73	void TOY_llist_free(void list, void (freeit)(void *data))
74	{
75	while (list) {
76	void *pop = TOY_llist_pop(&list);
77	if (freeit) freeit(pop);
78	else free(pop);
79
80	// End doubly linked list too.
81	if (list==pop) break;
82	}
83	}
84	//Override bbox's names
85	#define llist_pop TOY_llist_pop
86	#define llist_free TOY_llist_free
87
88	// Add an entry to the end off a doubly linked list
89	static
90	struct double_list dlist_add(struct double_list list, char data)
91	{
92	struct double_list *line = xmalloc(sizeof(struct double_list));
93
94	line->data = data;
95	if (*list) {
96	line->next = *list;
97	line->prev = (*list)->prev;
98	(*list)->prev->next = line;
99	(*list)->prev = line;
100	} else *list = line->next = line->prev = line;
101
102	return line;
103	}
104
105	// Ensure entire path exists.
106	// If mode != -1 set permissions on newly created dirs.
107	// Requires that path string be writable (for temporary null terminators).
108	static
109	void xmkpath(char *path, int mode)
110	{
111	char *p, old;
112	mode_t mask;
113	int rc;
114	struct stat st;
115
116	for (p = path; ; p++) {
117	if (!p \|\| p == '/') {
118	old = *p;
119	*p = rc = 0;
120	if (stat(path, &st) \|\| !S_ISDIR(st.st_mode)) {
121	if (mode != -1) {
122	mask = umask(0);
123	rc = mkdir(path, mode);
124	umask(mask);
125	} else rc = mkdir(path, 0777);
126	}
127	*p = old;
128	if(rc) bb_perror_msg_and_die("mkpath '%s'", path);
129	}
130	if (!*p) break;
131	}
132	}
133
134	// Slow, but small.
135	static
136	char get_rawline(int fd, long plen, char end)
137	{
138	char c, *buf = NULL;
139	long len = 0;
140
141	for (;;) {
142	if (1>read(fd, &c, 1)) break;
143	if (!(len & 63)) buf=xrealloc(buf, len+65);
144	if ((buf[len++]=c) == end) break;
145	}
146	if (buf) buf[len]=0;
147	if (plen) *plen = len;
148
149	return buf;
150	}
151
152	static
153	char *get_line(int fd)
154	{
155	long len;
156	char *buf = get_rawline(fd, &len, '\n');
157
158	if (buf && buf[--len]=='\n') buf[len]=0;
159
160	return buf;
161	}
162
163	// Copy the rest of in to out and close both files.
164	static
165	void xsendfile(int in, int out)
166	{
167	long len;
168	char buf[4096];
169
170	if (in<0) return;
171	for (;;) {
172	len = safe_read(in, buf, 4096);
173	if (len<1) break;
174	xwrite(out, buf, len);
175	}
176	}
177
178	// Copy the rest of the data and replace the original with the copy.
179	static
180	void replace_tempfile(int fdin, int fdout, char **tempname)
181	{
182	char temp = xstrdup(tempname);
183
184	temp[strlen(temp)-6]=0;
185	if (fdin != -1) {
186	xsendfile(fdin, fdout);
187	xclose(fdin);
188	}
189	xclose(fdout);
190	rename(*tempname, temp);
191	free(*tempname);
192	free(temp);
193	*tempname = NULL;
194	}
195
196	// Open a temporary file to copy an existing file into.
197	static
198	int copy_tempfile(int fdin, char name, char *tempname)
199	{
200	struct stat statbuf;
201	int fd;
202
203	*tempname = xasprintf("%sXXXXXX", name);
204	fd = mkstemp(*tempname);
205	if(-1 == fd) bb_perror_msg_and_die("no temp file");
206
207	// Set permissions of output file
208	fstat(fdin, &statbuf);
209	fchmod(fd, statbuf.st_mode);
210
211	return fd;
212	}
213
214	// Abort the copy and delete the temporary file.
215	static
216	void delete_tempfile(int fdin, int fdout, char **tempname)
217	{
218	close(fdin);
219	close(fdout);
220	unlink(*tempname);
221	free(*tempname);
222	*tempname = NULL;
223	}
224
225
226
227	struct globals {
228	char *infile;
229	long prefix;
230
231	struct double_list *current_hunk;
232	long oldline, oldlen, newline, newlen;
233	long linenum;
234	int context, state, filein, fileout, filepatch, hunknum;
235	char *tempname;
236
237	// was toys.foo:
238	int exitval;
239	};
240	#define TT (*ptr_to_globals)
241	#define INIT_TT() do { \
242	SET_PTR_TO_GLOBALS(xzalloc(sizeof(TT))); \
243	} while (0)
244
245
246	#define FLAG_STR "Rup:i:Nx"
247	/* FLAG_REVERSE must be == 1! Code uses this fact. */
248	#define FLAG_REVERSE (1 << 0)
249	#define FLAG_u (1 << 1)
250	#define FLAG_PATHLEN (1 << 2)
251	#define FLAG_INPUT (1 << 3)
252	#define FLAG_IGNORE (1 << 4)
253	//non-standard:
254	#define FLAG_DEBUG (1 << 5)
255
256	// Dispose of a line of input, either by writing it out or discarding it.
257
258	// state < 2: just free
259	// state = 2: write whole line to stderr
260	// state = 3: write whole line to fileout
261	// state > 3: write line+1 to fileout when *line != state
262
263	#define PATCH_DEBUG (option_mask32 & FLAG_DEBUG)
264
265	static void do_line(void *data)
266	{
267	struct double_list dlist = (struct double_list )data;
268
269	if (TT.state>1 && *dlist->data != TT.state)
270	fdprintf(TT.state == 2 ? 2 : TT.fileout,
271	"%s\n", dlist->data+(TT.state>3 ? 1 : 0));
272
273	if (PATCH_DEBUG) fdprintf(2, "DO %d: %s\n", TT.state, dlist->data);
274
275	free(dlist->data);
276	free(data);
277	}
278
279	static void finish_oldfile(void)
280	{
281	if (TT.tempname) replace_tempfile(TT.filein, TT.fileout, &TT.tempname);
282	TT.fileout = TT.filein = -1;
283	}
284
285	static void fail_hunk(void)
286	{
287	if (!TT.current_hunk) return;
288	TT.current_hunk->prev->next = 0;
289
290	fdprintf(2, "Hunk %d FAILED %ld/%ld.\n", TT.hunknum, TT.oldline, TT.newline);
291	TT.exitval = 1;
292
293	// If we got to this point, we've seeked to the end. Discard changes to
294	// this file and advance to next file.
295
296	TT.state = 2;
297	llist_free(TT.current_hunk, do_line);
298	TT.current_hunk = NULL;
299	delete_tempfile(TT.filein, TT.fileout, &TT.tempname);
300	TT.state = 0;
301	}
302
303	// Given a hunk of a unified diff, make the appropriate change to the file.
304	// This does not use the location information, but instead treats a hunk
305	// as a sort of regex. Copies data from input to output until it finds
306	// the change to be made, then outputs the changed data and returns.
307	// (Finding EOF first is an error.) This is a single pass operation, so
308	// multiple hunks must occur in order in the file.
309
310	static int apply_one_hunk(void)
311	{
312	struct double_list plist, buf = NULL, *check;
313	int matcheof = 0, reverse = option_mask32 & FLAG_REVERSE, backwarn = 0;
314	/* Do we try "dummy" revert to check whether
315	* to silently skip this hunk? Used to implement -N.
316	*/
317	int dummy_revert = 0;
318
319	// Break doubly linked list so we can use singly linked traversal function.
320	TT.current_hunk->prev->next = NULL;
321
322	// Match EOF if there aren't as many ending context lines as beginning
323	for (plist = TT.current_hunk; plist; plist = plist->next) {
324	if (plist->data[0]==' ') matcheof++;
325	else matcheof = 0;
326	if (PATCH_DEBUG) fdprintf(2, "HUNK:%s\n", plist->data);
327	}
328	matcheof = matcheof < TT.context;
329
330	if (PATCH_DEBUG) fdprintf(2,"MATCHEOF=%c\n", matcheof ? 'Y' : 'N');
331
332	// Loop through input data searching for this hunk. Match all context
333	// lines and all lines to be removed until we've found the end of a
334	// complete hunk.
335	plist = TT.current_hunk;
336	buf = NULL;
337	if (TT.context) for (;;) {
338	char *data = get_line(TT.filein);
339
340	TT.linenum++;
341
342	// Figure out which line of hunk to compare with next. (Skip lines
343	// of the hunk we'd be adding.)
344	while (plist && *plist->data == "+-"[reverse]) {
345	if (data && !strcmp(data, plist->data+1)) {
346	if (!backwarn) {
347	backwarn++;
348	if (option_mask32 & FLAG_IGNORE) {
349	dummy_revert = 1;
350	reverse ^= 1;
351	continue;
352	}
353	fdprintf(2,"Possibly reversed hunk %d at %ld\n",
354	TT.hunknum, TT.linenum);
355	}
356	}
357	plist = plist->next;
358	}
359
360	// Is this EOF?
361	if (!data) {
362	if (PATCH_DEBUG) fdprintf(2, "INEOF\n");
363
364	// Does this hunk need to match EOF?
365	if (!plist && matcheof) break;
366
367	// File ended before we found a place for this hunk.
368	fail_hunk();
369	goto done;
370	} else if (PATCH_DEBUG) fdprintf(2, "IN: %s\n", data);
371	check = dlist_add(&buf, data);
372
373	// Compare this line with next expected line of hunk.
374	// todo: teach the strcmp() to ignore whitespace.
375
376	// A match can fail because the next line doesn't match, or because
377	// we hit the end of a hunk that needed EOF, and this isn't EOF.
378
379	// If match failed, flush first line of buffered data and
380	// recheck buffered data for a new match until we find one or run
381	// out of buffer.
382
383	for (;;) {
384	if (!plist \|\| strcmp(check->data, plist->data+1)) {
385	// Match failed. Write out first line of buffered data and
386	// recheck remaining buffered data for a new match.
387
388	if (PATCH_DEBUG)
389	fdprintf(2, "NOT: %s\n", plist->data);
390
391	TT.state = 3;
392	check = llist_pop(&buf);
393	check->prev->next = buf;
394	buf->prev = check->prev;
395	do_line(check);
396	plist = TT.current_hunk;
397
398	// If we've reached the end of the buffer without confirming a
399	// match, read more lines.
400	if (check==buf) {
401	buf = 0;
402	break;
403	}
404	check = buf;
405	} else {
406	if (PATCH_DEBUG)
407	fdprintf(2, "MAYBE: %s\n", plist->data);
408	// This line matches. Advance plist, detect successful match.
409	plist = plist->next;
410	if (!plist && !matcheof) goto out;
411	check = check->next;
412	if (check == buf) break;
413	}
414	}
415	}
416	out:
417	// We have a match. Emit changed data.
418	TT.state = "-+"[reverse ^ dummy_revert];
419	llist_free(TT.current_hunk, do_line);
420	TT.current_hunk = NULL;
421	TT.state = 1;
422	done:
423	if (buf) {
424	buf->prev->next = NULL;
425	llist_free(buf, do_line);
426	}
427
428	return TT.state;
429	}
430
431	// Read a patch file and find hunks, opening/creating/deleting files.
432	// Call apply_one_hunk() on each hunk.
433
434	// state 0: Not in a hunk, look for +++.
435	// state 1: Found +++ file indicator, look for @@
436	// state 2: In hunk: counting initial context lines
437	// state 3: In hunk: getting body
438
439	int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
440	int patch_main(int argc UNUSED_PARAM, char **argv)
441	{
442	int opts;
443	int reverse, state = 0;
444	char oldname = NULL, newname = NULL;
445	char opt_p, opt_i;
446
447	INIT_TT();
448
449	opts = getopt32(argv, FLAG_STR, &opt_p, &opt_i);
450	argv += optind;
451	reverse = opts & FLAG_REVERSE;
452	TT.prefix = (opts & FLAG_PATHLEN) ? xatoi(opt_p) : 0; // can be negative!
453	TT.filein = TT.fileout = -1;
454	if (opts & FLAG_INPUT) {
455	TT.filepatch = xopen_stdin(opt_i);
456	} else {
457	if (argv[0] && argv[1]) {
458	TT.filepatch = xopen_stdin(argv[1]);
459	}
460	}
461	if (argv[0]) {
462	oldname = xstrdup(argv[0]);
463	newname = xstrdup(argv[0]);
464	}
465
466	// Loop through the lines in the patch
467	for(;;) {
468	char *patchline;
469
470	patchline = get_line(TT.filepatch);
471	if (!patchline) break;
472
473	// Other versions of patch accept damaged patches,
474	// so we need to also.
475	if (!*patchline) {
476	free(patchline);
477	patchline = xstrdup(" ");
478	}
479
480	// Are we assembling a hunk?
481	if (state >= 2) {
482	if (patchline==' ' \|\| patchline=='+' \|\| *patchline=='-') {
483	dlist_add(&TT.current_hunk, patchline);
484
485	if (*patchline != '+') TT.oldlen--;
486	if (*patchline != '-') TT.newlen--;
487
488	// Context line?
489	if (*patchline==' ' && state==2) TT.context++;
490	else state=3;
491
492	// If we've consumed all expected hunk lines, apply the hunk.
493
494	if (!TT.oldlen && !TT.newlen) state = apply_one_hunk();
495	continue;
496	}
497	fail_hunk();
498	state = 0;
499	continue;
500	}
501
502	// Open a new file?
503	if (!strncmp("--- ", patchline, 4) \|\| !strncmp("+++ ", patchline, 4)) {
504	char s, *name = reverse ? &newname : &oldname;
505	int i;
506
507	if (*patchline == '+') {
508	name = reverse ? &oldname : &newname;
509	state = 1;
510	}
511
512	finish_oldfile();
513
514	if (!argv[0]) {
515	free(*name);
516	// Trim date from end of filename (if any). We don't care.
517	for (s = patchline+4; s && s!='\t'; s++)
518	if (*s=='\\' && s[1]) s++;
519	i = atoi(s);
520	if (i>1900 && i<=1970)
521	*name = xstrdup("/dev/null");
522	else {
523	*s = 0;
524	*name = xstrdup(patchline+4);
525	}
526	}
527
528	// We defer actually opening the file because svn produces broken
529	// patches that don't signal they want to create a new file the
530	// way the patch man page says, so you have to read the first hunk
531	// and _guess_.
532
533	// Start a new hunk? Usually @@ -oldline,oldlen +newline,newlen @@
534	// but a missing ,value means the value is 1.
535	} else if (state == 1 && !strncmp("@@ -", patchline, 4)) {
536	int i;
537	char *s = patchline+4;
538
539	// Read oldline[,oldlen] +newline[,newlen]
540
541	TT.oldlen = TT.newlen = 1;
542	TT.oldline = strtol(s, &s, 10);
543	if (*s == ',') TT.oldlen=strtol(s+1, &s, 10);
544	TT.newline = strtol(s+2, &s, 10);
545	if (*s == ',') TT.newlen = strtol(s+1, &s, 10);
546
547	TT.context = 0;
548	state = 2;
549
550	// If this is the first hunk, open the file.
551	if (TT.filein == -1) {
552	int oldsum, newsum, del = 0;
553	char *name;
554
555	oldsum = TT.oldline + TT.oldlen;
556	newsum = TT.newline + TT.newlen;
557
558	name = reverse ? oldname : newname;
559
560	// We're deleting oldname if new file is /dev/null (before -p)
561	// or if new hunk is empty (zero context) after patching
562	if (!strcmp(name, "/dev/null") \|\| !(reverse ? oldsum : newsum))
563	{
564	name = reverse ? newname : oldname;
565	del++;
566	}
567
568	// handle -p path truncation.
569	for (i=0, s = name; *s;) {
570	if ((option_mask32 & FLAG_PATHLEN) && TT.prefix == i) break;
571	if (*(s++)=='/') {
572	name = s;
573	i++;
574	}
575	}
576
577	if (del) {
578	printf("removing %s\n", name);
579	xunlink(name);
580	state = 0;
581	// If we've got a file to open, do so.
582	} else if (!(option_mask32 & FLAG_PATHLEN) \|\| i <= TT.prefix) {
583	// If the old file was null, we're creating a new one.
584	if (!strcmp(oldname, "/dev/null") \|\| !oldsum) {
585	printf("creating %s\n", name);
586	s = strrchr(name, '/');
587	if (s) {
588	*s = 0;
589	xmkpath(name, -1);
590	*s = '/';
591	}
592	TT.filein = xopen3(name, O_CREAT\|O_EXCL\|O_RDWR, 0666);
593	} else {
594	printf("patching file %s\n", name);
595	TT.filein = xopen(name, O_RDWR);
596	}
597	TT.fileout = copy_tempfile(TT.filein, name, &TT.tempname);
598	TT.linenum = 0;
599	TT.hunknum = 0;
600	}
601	}
602
603	TT.hunknum++;
604
605	continue;
606	}
607
608	// If we didn't continue above, discard this line.
609	free(patchline);
610	}
611
612	finish_oldfile();
613
614	if (ENABLE_FEATURE_CLEAN_UP) {
615	close(TT.filepatch);
616	free(oldname);
617	free(newname);
618	}
619
620	return TT.exitval;
621	}