306 lines
		
	
	
		
			8.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			306 lines
		
	
	
		
			8.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* vi: set sw=4 ts=4: */
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| /*
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|  * busybox patch applet to handle the unified diff format.
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|  * Copyright (C) 2003 Glenn McGrath
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|  *
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|  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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|  *
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|  * This applet is written to work with patches generated by GNU diff,
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|  * where there is equivalent functionality busybox patch shall behave
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|  * as per GNU patch.
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|  *
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|  * There is a SUSv3 specification for patch, however it looks to be
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|  * incomplete, it doesnt even mention unified diff format.
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|  * http://www.opengroup.org/onlinepubs/007904975/utilities/patch.html
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|  *
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|  * Issues
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|  * - Non-interactive
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|  * - Patches must apply cleanly or patch (not just one hunk) will fail.
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|  * - Reject file isnt saved
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|  */
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| 
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| #include "libbb.h"
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| 
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| static unsigned copy_lines(FILE *src_stream, FILE *dst_stream, unsigned lines_count)
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| {
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| 	while (src_stream && lines_count) {
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| 		char *line;
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| 		line = xmalloc_fgets(src_stream);
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| 		if (line == NULL) {
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| 			break;
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| 		}
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| 		if (fputs(line, dst_stream) == EOF) {
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| 			bb_perror_msg_and_die("error writing to new file");
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| 		}
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| 		free(line);
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| 		lines_count--;
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| 	}
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| 	return lines_count;
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| }
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| 
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| /* If patch_level is -1 it will remove all directory names
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|  * char *line must be greater than 4 chars
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|  * returns NULL if the file doesnt exist or error
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|  * returns malloc'ed filename
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|  * NB: frees 1st argument!
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|  */
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| static char *extract_filename(char *line, int patch_level, const char *pat)
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| {
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| 	char *temp = NULL, *filename_start_ptr = line + 4;
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| 
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| 	if (strncmp(line, pat, 4) == 0) {
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| 		/* Terminate string at end of source filename */
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| 		line[strcspn(line, "\t\n\r")] = '\0';
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| 
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| 		/* Skip over (patch_level) number of leading directories */
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| 		while (patch_level--) {
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| 			temp = strchr(filename_start_ptr, '/');
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| 			if (!temp)
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| 				break;
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| 			filename_start_ptr = temp + 1;
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| 		}
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| 		temp = xstrdup(filename_start_ptr);
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| 	}
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| 	free(line);
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| 	return temp;
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| }
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| 
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| int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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| int patch_main(int argc UNUSED_PARAM, char **argv)
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| {
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| 	struct stat saved_stat;
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| 	char *patch_line;
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| 	FILE *patch_file;
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| 	int patch_level;
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| 	int ret = 0;
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| 	char plus = '+';
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| 	unsigned opt;
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| 	enum {
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| 		OPT_R = (1 << 2),
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| 		OPT_N = (1 << 3),
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| 		/*OPT_f = (1 << 4), ignored */
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| 		/*OPT_E = (1 << 5), ignored, this is the default */
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| 		/*OPT_g = (1 << 6), ignored */
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| 		OPT_dry_run = (1 << 7) * ENABLE_LONG_OPTS,
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| 	};
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| 
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| 	xfunc_error_retval = 2;
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| 	{
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| 		const char *p = "-1";
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| 		const char *i = "-"; /* compat */
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| #if ENABLE_LONG_OPTS
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| 		static const char patch_longopts[] ALIGN1 =
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| 			"strip\0"                 Required_argument "p"
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| 			"input\0"                 Required_argument "i"
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| 			"reverse\0"               No_argument       "R"
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| 			"forward\0"               No_argument       "N"
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| 		/* "Assume user knows what [s]he is doing, do not ask any questions": */
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| 			"force\0"                 No_argument       "f" /*ignored*/
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| # if ENABLE_DESKTOP
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| 			"remove-empty-files\0"    No_argument       "E" /*ignored*/
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| 		/* "Controls actions when a file is under RCS or SCCS control,
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| 		 * and does not exist or is read-only and matches the default version,
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| 		 * or when a file is under ClearCase control and does not exist..."
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| 		 * IOW: rather obscure option.
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| 		 * But Gentoo's portage does use -g0 */
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| 			"get\0"                   Required_argument "g" /*ignored*/
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| # endif
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| 			"dry-run\0"               No_argument       "\xfd"
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| # if ENABLE_DESKTOP
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| 			"backup-if-mismatch\0"    No_argument       "\xfe" /*ignored*/
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| 			"no-backup-if-mismatch\0" No_argument       "\xff" /*ignored*/
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| # endif
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| 			;
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| #endif
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| 		/* -f,-E,-g are ignored */
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| 		opt = getopt32long(argv, "p:i:RN""fEg:", patch_longopts, &p, &i, NULL);
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| 		if (opt & OPT_R)
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| 			plus = '-';
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| 		patch_level = xatoi(p); /* can be negative! */
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| 		patch_file = xfopen_stdin(i);
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| 	}
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| 
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| 	patch_line = xmalloc_fgetline(patch_file);
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| 	while (patch_line) {
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| 		FILE *src_stream;
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| 		FILE *dst_stream;
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| 		//char *old_filename;
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| 		char *new_filename;
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| 		char *backup_filename = NULL;
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| 		unsigned src_cur_line = 1;
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| 		unsigned dst_cur_line = 0;
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| 		unsigned dst_beg_line;
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| 		unsigned bad_hunk_count = 0;
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| 		unsigned hunk_count = 0;
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| 		smallint copy_trailing_lines_flag = 0;
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| 
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| 		/* Skip everything upto the "---" marker
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| 		 * No need to parse the lines "Only in <dir>", and "diff <args>"
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| 		 */
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| 		do {
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| 			/* Extract the filename used before the patch was generated */
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| 			new_filename = extract_filename(patch_line, patch_level, "--- ");
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| 			// was old_filename above
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| 			patch_line = xmalloc_fgetline(patch_file);
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| 			if (!patch_line) goto quit;
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| 		} while (!new_filename);
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| 		free(new_filename); // "source" filename is irrelevant
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| 
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| 		new_filename = extract_filename(patch_line, patch_level, "+++ ");
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| 		if (!new_filename) {
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| 			bb_error_msg_and_die("invalid patch");
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| 		}
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| 
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| 		/* Get access rights from the file to be patched */
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| 		if (stat(new_filename, &saved_stat) != 0) {
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| 			char *slash = strrchr(new_filename, '/');
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| 			if (slash) {
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| 				/* Create leading directories */
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| 				*slash = '\0';
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| 				bb_make_directory(new_filename, -1, FILEUTILS_RECUR);
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| 				*slash = '/';
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| 			}
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| 			src_stream = NULL;
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| 			saved_stat.st_mode = 0644;
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| 		} else if (!(opt & OPT_dry_run)) {
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| 			backup_filename = xasprintf("%s.orig", new_filename);
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| 			xrename(new_filename, backup_filename);
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| 			src_stream = xfopen_for_read(backup_filename);
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| 		} else
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| 			src_stream = xfopen_for_read(new_filename);
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| 
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| 		if (opt & OPT_dry_run) {
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| 			dst_stream = xfopen_for_write("/dev/null");
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| 		} else {
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| 			dst_stream = xfopen_for_write(new_filename);
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| 			fchmod(fileno(dst_stream), saved_stat.st_mode);
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| 		}
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| 
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| 		printf("patching file %s\n", new_filename);
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| 
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| 		/* Handle all hunks for this file */
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| 		patch_line = xmalloc_fgets(patch_file);
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| 		while (patch_line) {
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| 			unsigned count;
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| 			unsigned src_beg_line;
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| 			unsigned hunk_offset_start;
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| 			unsigned src_last_line = 1;
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| 			unsigned dst_last_line = 1;
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| 
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| 			if ((sscanf(patch_line, "@@ -%u,%u +%u,%u", &src_beg_line, &src_last_line, &dst_beg_line, &dst_last_line) < 3)
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| 			 && (sscanf(patch_line, "@@ -%u +%u,%u", &src_beg_line, &dst_beg_line, &dst_last_line) < 2)
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| 			) {
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| 				/* No more hunks for this file */
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| 				break;
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| 			}
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| 			if (plus != '+') {
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| 				/* reverse patch */
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| 				unsigned tmp = src_last_line;
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| 				src_last_line = dst_last_line;
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| 				dst_last_line = tmp;
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| 				tmp = src_beg_line;
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| 				src_beg_line = dst_beg_line;
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| 				dst_beg_line = tmp;
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| 			}
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| 			hunk_count++;
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| 
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| 			if (src_beg_line && dst_beg_line) {
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| 				/* Copy unmodified lines upto start of hunk */
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| 				/* src_beg_line will be 0 if it's a new file */
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| 				count = src_beg_line - src_cur_line;
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| 				if (copy_lines(src_stream, dst_stream, count)) {
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| 					bb_error_msg_and_die("bad src file");
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| 				}
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| 				src_cur_line += count;
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| 				dst_cur_line += count;
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| 				copy_trailing_lines_flag = 1;
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| 			}
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| 			src_last_line += hunk_offset_start = src_cur_line;
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| 			dst_last_line += dst_cur_line;
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| 
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| 			while (1) {
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| 				free(patch_line);
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| 				patch_line = xmalloc_fgets(patch_file);
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| 				if (patch_line == NULL)
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| 					break; /* EOF */
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| 				if (!*patch_line) {
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| 					/* whitespace-damaged patch with "" lines */
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| 					free(patch_line);
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| 					patch_line = xstrdup(" ");
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| 				}
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| 				if ((*patch_line != '-') && (*patch_line != '+')
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| 				 && (*patch_line != ' ')
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| 				) {
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| 					break; /* End of hunk */
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| 				}
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| 				if (*patch_line != plus) { /* '-' or ' ' */
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| 					char *src_line = NULL;
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| 					if (src_cur_line == src_last_line)
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| 						break;
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| 					if (src_stream) {
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| 						src_line = xmalloc_fgets(src_stream);
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| 						if (src_line) {
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| 							int diff = strcmp(src_line, patch_line + 1);
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| 							src_cur_line++;
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| 							free(src_line);
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| 							if (diff)
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| 								src_line = NULL;
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| 						}
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| 					}
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| 					/* Do not patch an already patched hunk with -N */
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| 					if (src_line == 0 && (opt & OPT_N)) {
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| 						continue;
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| 					}
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| 					if (!src_line) {
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| 						bb_error_msg("hunk #%u FAILED at %u", hunk_count, hunk_offset_start);
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| 						bad_hunk_count++;
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| 						break;
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| 					}
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| 					if (*patch_line != ' ') { /* '-' */
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| 						continue;
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| 					}
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| 				}
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| 				if (dst_cur_line == dst_last_line)
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| 					break;
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| 				fputs(patch_line + 1, dst_stream);
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| 				dst_cur_line++;
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| 			} /* end of while loop handling one hunk */
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| 		} /* end of while loop handling one file */
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| 
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| 		/* Cleanup last patched file */
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| 		if (copy_trailing_lines_flag) {
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| 			copy_lines(src_stream, dst_stream, (unsigned)(-1));
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| 		}
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| 		if (src_stream) {
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| 			fclose(src_stream);
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| 		}
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| 		fclose(dst_stream);
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| 		if (bad_hunk_count) {
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| 			ret = 1;
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| 			bb_error_msg("%u out of %u hunk FAILED", bad_hunk_count, hunk_count);
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| 		} else {
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| 			/* It worked, we can remove the backup */
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| 			if (backup_filename) {
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| 				unlink(backup_filename);
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| 			}
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| 			if (!(opt & OPT_dry_run)
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| 			 && ((dst_cur_line == 0) || (dst_beg_line == 0))
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| 			) {
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| 				/* The new patched file is empty, remove it */
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| 				xunlink(new_filename);
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| 				// /* old_filename and new_filename may be the same file */
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| 				// unlink(old_filename);
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| 			}
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| 		}
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| 		free(backup_filename);
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| 		//free(old_filename);
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| 		free(new_filename);
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| 	} /* end of "while there are patch lines" */
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|  quit:
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| 	/* 0 = SUCCESS
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| 	 * 1 = Some hunks failed
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| 	 * 2 = More serious problems (exited earlier)
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| 	 */
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| 	return ret;
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| }
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