editors/patch_bbox.c - busybox - Git at Google

 /* vi: set sw=4 ts=4: */
 /*
  * busybox patch applet to handle the unified diff format.
  * Copyright (C) 2003 Glenn McGrath
  *
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  *
  * This applet is written to work with patches generated by GNU diff,
  * where there is equivalent functionality busybox patch shall behave
  * as per GNU patch.
  *
  * There is a SUSv3 specification for patch, however it looks to be
  * incomplete, it doesnt even mention unified diff format.
  * http://www.opengroup.org/onlinepubs/007904975/utilities/patch.html
  *
  * Issues
  * - Non-interactive
  * - Patches must apply cleanly or patch (not just one hunk) will fail.
  * - Reject file isnt saved
  */

 #include "libbb.h"

 static unsigned copy_lines(FILE *src_stream, FILE *dst_stream, unsigned lines_count)
 {
 	while (src_stream && lines_count) {
 		char *line;
 		line = xmalloc_fgets(src_stream);
 		if (line == NULL) {
 			break;
 		}
 		if (fputs(line, dst_stream) == EOF) {
 			bb_perror_msg_and_die("error writing to new file");
 		}
 		free(line);
 		lines_count--;
 	}
 	return lines_count;
 }

 /* If patch_level is -1 it will remove all directory names
  * char *line must be greater than 4 chars
  * returns NULL if the file doesnt exist or error
  * returns malloc'ed filename
  * NB: frees 1st argument!
  */
 static char *extract_filename(char *line, int patch_level, const char *pat)
 {
 	char *temp = NULL, *filename_start_ptr = line + 4;

 	if (strncmp(line, pat, 4) == 0) {
 		/* Terminate string at end of source filename */
 		line[strcspn(line, "\t\n\r")] = '\0';

 		/* Skip over (patch_level) number of leading directories */
 		while (patch_level--) {
 			temp = strchr(filename_start_ptr, '/');
 			if (!temp)
 				break;
 			filename_start_ptr = temp + 1;
 		}
 		temp = xstrdup(filename_start_ptr);
 	}
 	free(line);
 	return temp;
 }

 int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int patch_main(int argc UNUSED_PARAM, char **argv)
 {
 	struct stat saved_stat;
 	char *patch_line;
 	FILE *patch_file;
 	int patch_level;
 	int ret = 0;
 	char plus = '+';
 	unsigned opt;
 	enum {
 		OPT_R = (1 << 2),
 		OPT_N = (1 << 3),
 		/*OPT_f = (1 << 4), ignored */
 		/*OPT_E = (1 << 5), ignored, this is the default */
 		/*OPT_g = (1 << 6), ignored */
 		OPT_dry_run = (1 << 7) * ENABLE_LONG_OPTS,
 	};

 	xfunc_error_retval = 2;
 	{
 		const char *p = "-1";
 		const char *i = "-"; /* compat */
 #if ENABLE_LONG_OPTS
 		static const char patch_longopts[] ALIGN1 =
 			"strip\0"                 Required_argument "p"
 			"input\0"                 Required_argument "i"
 			"reverse\0"               No_argument       "R"
 			"forward\0"               No_argument       "N"
 		/* "Assume user knows what [s]he is doing, do not ask any questions": */
 			"force\0"                 No_argument       "f" /*ignored*/
 # if ENABLE_DESKTOP
 			"remove-empty-files\0"    No_argument       "E" /*ignored*/
 		/* "Controls actions when a file is under RCS or SCCS control,
 		 * and does not exist or is read-only and matches the default version,
 		 * or when a file is under ClearCase control and does not exist..."
 		 * IOW: rather obscure option.
 		 * But Gentoo's portage does use -g0 */
 			"get\0"                   Required_argument "g" /*ignored*/
 # endif
 			"dry-run\0"               No_argument       "\xfd"
 # if ENABLE_DESKTOP
 			"backup-if-mismatch\0"    No_argument       "\xfe" /*ignored*/
 			"no-backup-if-mismatch\0" No_argument       "\xff" /*ignored*/
 # endif
 			;
 #endif
 		/* -f,-E,-g are ignored */
 		opt = getopt32long(argv, "p:i:RN""fEg:", patch_longopts, &p, &i, NULL);
 		if (opt & OPT_R)
 			plus = '-';
 		patch_level = xatoi(p); /* can be negative! */
 		patch_file = xfopen_stdin(i);
 	}

 	patch_line = xmalloc_fgetline(patch_file);
 	while (patch_line) {
 		FILE *src_stream;
 		FILE *dst_stream;
 		//char *old_filename;
 		char *new_filename;
 		char *backup_filename = NULL;
 		unsigned src_cur_line = 1;
 		unsigned dst_cur_line = 0;
 		unsigned dst_beg_line;
 		unsigned bad_hunk_count = 0;
 		unsigned hunk_count = 0;
 		smallint copy_trailing_lines_flag = 0;

 		/* Skip everything upto the "---" marker
 		 * No need to parse the lines "Only in <dir>", and "diff <args>"
 		 */
 		do {
 			/* Extract the filename used before the patch was generated */
 			new_filename = extract_filename(patch_line, patch_level, "--- ");
 			// was old_filename above
 			patch_line = xmalloc_fgetline(patch_file);
 			if (!patch_line) goto quit;
 		} while (!new_filename);
 		free(new_filename); // "source" filename is irrelevant

 		new_filename = extract_filename(patch_line, patch_level, "+++ ");
 		if (!new_filename) {
 			bb_error_msg_and_die("invalid patch");
 		}

 		/* Get access rights from the file to be patched */
 		if (stat(new_filename, &saved_stat) != 0) {
 			char *slash = strrchr(new_filename, '/');
 			if (slash) {
 				/* Create leading directories */
 				*slash = '\0';
 				bb_make_directory(new_filename, -1, FILEUTILS_RECUR);
 				*slash = '/';
 			}
 			src_stream = NULL;
 			saved_stat.st_mode = 0644;
 		} else if (!(opt & OPT_dry_run)) {
 			backup_filename = xasprintf("%s.orig", new_filename);
 			xrename(new_filename, backup_filename);
 			src_stream = xfopen_for_read(backup_filename);
 		} else
 			src_stream = xfopen_for_read(new_filename);

 		if (opt & OPT_dry_run) {
 			dst_stream = xfopen_for_write("/dev/null");
 		} else {
 			dst_stream = xfopen_for_write(new_filename);
 			fchmod(fileno(dst_stream), saved_stat.st_mode);
 		}

 		printf("patching file %s\n", new_filename);

 		/* Handle all hunks for this file */
 		patch_line = xmalloc_fgets(patch_file);
 		while (patch_line) {
 			unsigned count;
 			unsigned src_beg_line;
 			unsigned hunk_offset_start;
 			unsigned src_last_line = 1;
 			unsigned dst_last_line = 1;

 			if ((sscanf(patch_line, "@@ -%u,%u +%u,%u", &src_beg_line, &src_last_line, &dst_beg_line, &dst_last_line) < 3)
 			 && (sscanf(patch_line, "@@ -%u +%u,%u", &src_beg_line, &dst_beg_line, &dst_last_line) < 2)
 			) {
 				/* No more hunks for this file */
 				break;
 			}
 			if (plus != '+') {
 				/* reverse patch */
 				unsigned tmp = src_last_line;
 				src_last_line = dst_last_line;
 				dst_last_line = tmp;
 				tmp = src_beg_line;
 				src_beg_line = dst_beg_line;
 				dst_beg_line = tmp;
 			}
 			hunk_count++;

 			if (src_beg_line && dst_beg_line) {
 				/* Copy unmodified lines upto start of hunk */
 				/* src_beg_line will be 0 if it's a new file */
 				count = src_beg_line - src_cur_line;
 				if (copy_lines(src_stream, dst_stream, count)) {
 					bb_error_msg_and_die("bad src file");
 				}
 				src_cur_line += count;
 				dst_cur_line += count;
 				copy_trailing_lines_flag = 1;
 			}
 			src_last_line += hunk_offset_start = src_cur_line;
 			dst_last_line += dst_cur_line;

 			while (1) {
 				free(patch_line);
 				patch_line = xmalloc_fgets(patch_file);
 				if (patch_line == NULL)
 					break; /* EOF */
 				if (!*patch_line) {
 					/* whitespace-damaged patch with "" lines */
 					free(patch_line);
 					patch_line = xstrdup(" ");
 				}
 				if ((*patch_line != '-') && (*patch_line != '+')
 				 && (*patch_line != ' ')
 				) {
 					break; /* End of hunk */
 				}
 				if (*patch_line != plus) { /* '-' or ' ' */
 					char *src_line = NULL;
 					if (src_cur_line == src_last_line)
 						break;
 					if (src_stream) {
 						src_line = xmalloc_fgets(src_stream);
 						if (src_line) {
 							int diff = strcmp(src_line, patch_line + 1);
 							src_cur_line++;
 							free(src_line);
 							if (diff)
 								src_line = NULL;
 						}
 					}
 					/* Do not patch an already patched hunk with -N */
 					if (src_line == 0 && (opt & OPT_N)) {
 						continue;
 					}
 					if (!src_line) {
 						bb_error_msg("hunk #%u FAILED at %u", hunk_count, hunk_offset_start);
 						bad_hunk_count++;
 						break;
 					}
 					if (*patch_line != ' ') { /* '-' */
 						continue;
 					}
 				}
 				if (dst_cur_line == dst_last_line)
 					break;
 				fputs(patch_line + 1, dst_stream);
 				dst_cur_line++;
 			} /* end of while loop handling one hunk */
 		} /* end of while loop handling one file */

 		/* Cleanup last patched file */
 		if (copy_trailing_lines_flag) {
 			copy_lines(src_stream, dst_stream, (unsigned)(-1));
 		}
 		if (src_stream) {
 			fclose(src_stream);
 		}
 		fclose(dst_stream);
 		if (bad_hunk_count) {
 			ret = 1;
 			bb_error_msg("%u out of %u hunk FAILED", bad_hunk_count, hunk_count);
 		} else {
 			/* It worked, we can remove the backup */
 			if (backup_filename) {
 				unlink(backup_filename);
 			}
 			if (!(opt & OPT_dry_run)
 			 && ((dst_cur_line == 0) || (dst_beg_line == 0))
 			) {
 				/* The new patched file is empty, remove it */
 				xunlink(new_filename);
 				// /* old_filename and new_filename may be the same file */
 				// unlink(old_filename);
 			}
 		}
 		free(backup_filename);
 		//free(old_filename);
 		free(new_filename);
 	} /* end of "while there are patch lines" */
  quit:
 	/* 0 = SUCCESS
 	 * 1 = Some hunks failed
 	 * 2 = More serious problems (exited earlier)
 	 */
 	return ret;
 }
	/* vi: set sw=4 ts=4: */
	/*
	* busybox patch applet to handle the unified diff format.
	* Copyright (C) 2003 Glenn McGrath
	*
	* Licensed under GPLv2 or later, see file LICENSE in this source tree.
	*
	* This applet is written to work with patches generated by GNU diff,
	* where there is equivalent functionality busybox patch shall behave
	* as per GNU patch.
	*
	* There is a SUSv3 specification for patch, however it looks to be
	* incomplete, it doesnt even mention unified diff format.
	* http://www.opengroup.org/onlinepubs/007904975/utilities/patch.html
	*
	* Issues
	* - Non-interactive
	* - Patches must apply cleanly or patch (not just one hunk) will fail.
	* - Reject file isnt saved
	*/

	#include "libbb.h"

	static unsigned copy_lines(FILE src_stream, FILE dst_stream, unsigned lines_count)
	{
	while (src_stream && lines_count) {
	char *line;
	line = xmalloc_fgets(src_stream);
	if (line == NULL) {
	break;
	}
	if (fputs(line, dst_stream) == EOF) {
	bb_perror_msg_and_die("error writing to new file");
	}
	free(line);
	lines_count--;
	}
	return lines_count;
	}

	/* If patch_level is -1 it will remove all directory names
	* char *line must be greater than 4 chars
	* returns NULL if the file doesnt exist or error
	* returns malloc'ed filename
	* NB: frees 1st argument!
	*/
	static char extract_filename(char line, int patch_level, const char *pat)
	{
	char temp = NULL, filename_start_ptr = line + 4;

	if (strncmp(line, pat, 4) == 0) {
	/* Terminate string at end of source filename */
	line[strcspn(line, "\t\n\r")] = '\0';

	/* Skip over (patch_level) number of leading directories */
	while (patch_level--) {
	temp = strchr(filename_start_ptr, '/');
	if (!temp)
	break;
	filename_start_ptr = temp + 1;
	}
	temp = xstrdup(filename_start_ptr);
	}
	free(line);
	return temp;
	}

	int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int patch_main(int argc UNUSED_PARAM, char **argv)
	{
	struct stat saved_stat;
	char *patch_line;
	FILE *patch_file;
	int patch_level;
	int ret = 0;
	char plus = '+';
	unsigned opt;
	enum {
	OPT_R = (1 << 2),
	OPT_N = (1 << 3),
	/OPT_f = (1 << 4), ignored /
	/OPT_E = (1 << 5), ignored, this is the default /
	/OPT_g = (1 << 6), ignored /
	OPT_dry_run = (1 << 7) * ENABLE_LONG_OPTS,
	};

	xfunc_error_retval = 2;
	{
	const char *p = "-1";
	const char i = "-"; / compat */
	#if ENABLE_LONG_OPTS
	static const char patch_longopts[] ALIGN1 =
	"strip\0" Required_argument "p"
	"input\0" Required_argument "i"
	"reverse\0" No_argument "R"
	"forward\0" No_argument "N"
	/* "Assume user knows what [s]he is doing, do not ask any questions": */
	"force\0" No_argument "f" /ignored/
	# if ENABLE_DESKTOP
	"remove-empty-files\0" No_argument "E" /ignored/
	/* "Controls actions when a file is under RCS or SCCS control,
	* and does not exist or is read-only and matches the default version,
	* or when a file is under ClearCase control and does not exist..."
	* IOW: rather obscure option.
	* But Gentoo's portage does use -g0 */
	"get\0" Required_argument "g" /ignored/
	# endif
	"dry-run\0" No_argument "\xfd"
	# if ENABLE_DESKTOP
	"backup-if-mismatch\0" No_argument "\xfe" /ignored/
	"no-backup-if-mismatch\0" No_argument "\xff" /ignored/
	# endif
	;
	#endif
	/* -f,-E,-g are ignored */
	opt = getopt32long(argv, "p:i:RN""fEg:", patch_longopts, &p, &i, NULL);
	if (opt & OPT_R)
	plus = '-';
	patch_level = xatoi(p); /* can be negative! */
	patch_file = xfopen_stdin(i);
	}

	patch_line = xmalloc_fgetline(patch_file);
	while (patch_line) {
	FILE *src_stream;
	FILE *dst_stream;
	//char *old_filename;
	char *new_filename;
	char *backup_filename = NULL;
	unsigned src_cur_line = 1;
	unsigned dst_cur_line = 0;
	unsigned dst_beg_line;
	unsigned bad_hunk_count = 0;
	unsigned hunk_count = 0;
	smallint copy_trailing_lines_flag = 0;

	/* Skip everything upto the "---" marker
	* No need to parse the lines "Only in <dir>", and "diff <args>"
	*/
	do {
	/* Extract the filename used before the patch was generated */
	new_filename = extract_filename(patch_line, patch_level, "--- ");
	// was old_filename above
	patch_line = xmalloc_fgetline(patch_file);
	if (!patch_line) goto quit;
	} while (!new_filename);
	free(new_filename); // "source" filename is irrelevant

	new_filename = extract_filename(patch_line, patch_level, "+++ ");
	if (!new_filename) {
	bb_error_msg_and_die("invalid patch");
	}

	/* Get access rights from the file to be patched */
	if (stat(new_filename, &saved_stat) != 0) {
	char *slash = strrchr(new_filename, '/');
	if (slash) {
	/* Create leading directories */
	*slash = '\0';
	bb_make_directory(new_filename, -1, FILEUTILS_RECUR);
	*slash = '/';
	}
	src_stream = NULL;
	saved_stat.st_mode = 0644;
	} else if (!(opt & OPT_dry_run)) {
	backup_filename = xasprintf("%s.orig", new_filename);
	xrename(new_filename, backup_filename);
	src_stream = xfopen_for_read(backup_filename);
	} else
	src_stream = xfopen_for_read(new_filename);

	if (opt & OPT_dry_run) {
	dst_stream = xfopen_for_write("/dev/null");
	} else {
	dst_stream = xfopen_for_write(new_filename);
	fchmod(fileno(dst_stream), saved_stat.st_mode);
	}

	printf("patching file %s\n", new_filename);

	/* Handle all hunks for this file */
	patch_line = xmalloc_fgets(patch_file);
	while (patch_line) {
	unsigned count;
	unsigned src_beg_line;
	unsigned hunk_offset_start;
	unsigned src_last_line = 1;
	unsigned dst_last_line = 1;

	if ((sscanf(patch_line, "@@ -%u,%u +%u,%u", &src_beg_line, &src_last_line, &dst_beg_line, &dst_last_line) < 3)
	&& (sscanf(patch_line, "@@ -%u +%u,%u", &src_beg_line, &dst_beg_line, &dst_last_line) < 2)
	) {
	/* No more hunks for this file */
	break;
	}
	if (plus != '+') {
	/* reverse patch */
	unsigned tmp = src_last_line;
	src_last_line = dst_last_line;
	dst_last_line = tmp;
	tmp = src_beg_line;
	src_beg_line = dst_beg_line;
	dst_beg_line = tmp;
	}
	hunk_count++;

	if (src_beg_line && dst_beg_line) {
	/* Copy unmodified lines upto start of hunk */
	/* src_beg_line will be 0 if it's a new file */
	count = src_beg_line - src_cur_line;
	if (copy_lines(src_stream, dst_stream, count)) {
	bb_error_msg_and_die("bad src file");
	}
	src_cur_line += count;
	dst_cur_line += count;
	copy_trailing_lines_flag = 1;
	}
	src_last_line += hunk_offset_start = src_cur_line;
	dst_last_line += dst_cur_line;

	while (1) {
	free(patch_line);
	patch_line = xmalloc_fgets(patch_file);
	if (patch_line == NULL)
	break; /* EOF */
	if (!*patch_line) {
	/* whitespace-damaged patch with "" lines */
	free(patch_line);
	patch_line = xstrdup(" ");
	}
	if ((patch_line != '-') && (patch_line != '+')
	&& (*patch_line != ' ')
	) {
	break; /* End of hunk */
	}
	if (patch_line != plus) { / '-' or ' ' */
	char *src_line = NULL;
	if (src_cur_line == src_last_line)
	break;
	if (src_stream) {
	src_line = xmalloc_fgets(src_stream);
	if (src_line) {
	int diff = strcmp(src_line, patch_line + 1);
	src_cur_line++;
	free(src_line);
	if (diff)
	src_line = NULL;
	}
	}
	/* Do not patch an already patched hunk with -N */
	if (src_line == 0 && (opt & OPT_N)) {
	continue;
	}
	if (!src_line) {
	bb_error_msg("hunk #%u FAILED at %u", hunk_count, hunk_offset_start);
	bad_hunk_count++;
	break;
	}
	if (patch_line != ' ') { / '-' */
	continue;
	}
	}
	if (dst_cur_line == dst_last_line)
	break;
	fputs(patch_line + 1, dst_stream);
	dst_cur_line++;
	} /* end of while loop handling one hunk */
	} /* end of while loop handling one file */

	/* Cleanup last patched file */
	if (copy_trailing_lines_flag) {
	copy_lines(src_stream, dst_stream, (unsigned)(-1));
	}
	if (src_stream) {
	fclose(src_stream);
	}
	fclose(dst_stream);
	if (bad_hunk_count) {
	ret = 1;
	bb_error_msg("%u out of %u hunk FAILED", bad_hunk_count, hunk_count);
	} else {
	/* It worked, we can remove the backup */
	if (backup_filename) {
	unlink(backup_filename);
	}
	if (!(opt & OPT_dry_run)
	&& ((dst_cur_line == 0) \|\| (dst_beg_line == 0))
	) {
	/* The new patched file is empty, remove it */
	xunlink(new_filename);
	// /* old_filename and new_filename may be the same file */
	// unlink(old_filename);
	}
	}
	free(backup_filename);
	//free(old_filename);
	free(new_filename);
	} /* end of "while there are patch lines" */
	quit:
	/* 0 = SUCCESS
	* 1 = Some hunks failed
	* 2 = More serious problems (exited earlier)
	*/
	return ret;
	}