patch: add Rob's version for reference, it may handle fuzz and offsets

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 559 insertions, 0 deletions

diff --git a/editors/patch_toybox.c b/editors/patch_toybox.c
new file mode 100644
index 0000000..f1e0de6
--- /dev/null
+++ b/editors/patch_toybox.c
@@ -0,0 +1,559 @@
+/* Adapted from toybox's patch. Currently unused */
+
+/* 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
+ * -N ignore already applied
+ * -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, "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;
+	}
+}
+
+// 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 {
+	struct double_list *plines;
+	long linenum;
+	int context;
+	int hunknum;
+	int filein;
+	int fileout;
+	int state;
+	char *tempname;
+	smallint exitval;
+};
+#define TT (*ptr_to_globals)
+#define INIT_TT() do { \
+	SET_PTR_TO_GLOBALS(xzalloc(sizeof(TT))); \
+} while (0)
+
+
+//bbox had: "p:i:RN"
+#define FLAG_STR "Rup:i:"
+/* 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)
+
+// 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
+
+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));
+
+	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.plines) return;
+	TT.plines->prev->next = 0;
+
+	fdprintf(2, "Hunk %d FAILED.\n", TT.hunknum);
+	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;
+	TOY_llist_free(TT.plines, do_line);
+	TT.plines = NULL;
+	delete_tempfile(TT.filein, TT.fileout, &TT.tempname);
+	TT.state = 0;
+}
+
+static int apply_hunk(void)
+{
+	struct double_list *plist, *buf = NULL, *check;
+	int i = 0, backwards = 0, matcheof = 0,
+		reverse = option_mask32 & FLAG_REVERSE;
+
+	// Break doubly linked list so we can use singly linked traversal function.
+	TT.plines->prev->next = NULL;
+
+	// Match EOF if there aren't as many ending context lines as beginning
+	for (plist = TT.plines; plist; plist = plist->next) {
+		if (plist->data[0]==' ') i++;
+		else i = 0;
+	}
+	if (i < TT.context) matcheof++;
+
+	// Search for a place to apply this hunk.  Match all context lines and
+	// lines to be removed.
+	plist = TT.plines;
+	buf = NULL;
+	i = 0;
+
+	// Start of for loop
+	if (TT.context) for (;;) {
+		char *data = get_line(TT.filein);
+
+		TT.linenum++;
+
+		// Skip lines of the hunk we'd be adding.
+		while (plist && *plist->data == "+-"[reverse]) {
+			if (data && !strcmp(data, plist->data+1)) {
+				if (++backwards == TT.context)
+					fdprintf(2,"Possibly reversed hunk %d at %ld\n",
+						TT.hunknum, TT.linenum);
+			} else backwards=0;
+			plist = plist->next;
+		}
+
+		// Is this EOF?
+		if (!data) {
+			// 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;
+		}
+		check = dlist_add(&buf, data);
+
+		// todo: teach the strcmp() to ignore whitespace.
+
+		for (;;) {
+			// If we hit the end of a hunk that needed EOF and this isn't EOF,
+			// or next line doesn't match, flush first line of buffered data and
+			// recheck match until we find a new match or run out of buffer.
+
+			if (!plist || strcmp(check->data, plist->data+1)) {
+				// First line isn't a match, write it out.
+				TT.state = 3;
+				check = TOY_llist_pop(&buf);
+				check->prev->next = buf;
+				buf->prev = check->prev;
+				do_line(check);
+				plist = TT.plines;
+
+				// Out of buffered lines?
+				if (check==buf) {
+					buf = 0;
+					break;
+				}
+				check = buf;
+			} else {
+				// This line matches.  Advance plist, detect successful match.
+				plist = plist->next;
+				if (!plist && !matcheof) goto out;
+				check = check->next;
+				if (check == buf) break;
+			}
+		}
+	}
+out:
+	// Got it.  Emit changed data.
+	TT.state = "-+"[reverse];
+	TOY_llist_free(TT.plines, do_line);
+	TT.plines = NULL;
+	TT.state = 1;
+done:
+	if (buf) {
+		buf->prev->next = NULL;
+		TOY_llist_free(buf, do_line);
+	}
+
+	return TT.state;
+}
+
+// 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;
+	int prefix;
+
+	long oldline = 0, oldlen = 0, newline = 0, newlen = 0;
+
+	INIT_TT();
+
+	opts = getopt32(argv, FLAG_STR, &opt_p, &opt_i);
+	reverse = opts & FLAG_REVERSE;
+
+	if (opts & FLAG_INPUT) xmove_fd(xopen(opt_i, O_RDONLY), STDIN_FILENO);
+	prefix = (opts & FLAG_PATHLEN) ? xatoi(opt_p) : 0; // can be negative!
+	TT.filein = TT.fileout = -1;
+
+	// Loop through the lines in the patch
+	for(;;) {
+		char *patchline;
+
+		patchline = get_line(STDIN_FILENO);
+		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.plines, patchline);
+
+				if (*patchline != '+') oldlen--;
+				if (*patchline != '-') newlen--;
+
+				// Context line?
+				if (*patchline==' ' && state==2) TT.context++;
+				else state=3;
+
+				// If we've consumed all expected hunk lines, apply the hunk.
+				if (!oldlen && !newlen) state = apply_hunk();
+				continue;
+			}
+			fail_hunk();
+			state = 0;
+			continue;
+		}
+
+		// Open a new file?
+		if (!strncmp("--- ", patchline, 4) || !strncmp("+++ ", patchline, 4)) {
+			char *s, **name = &oldname;
+			int i;
+
+			if (*patchline == '+') {
+				name = &newname;
+				state = 1;
+			}
+
+			free(*name);
+			finish_oldfile();
+
+			// 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 && 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?
+		} else if (state == 1 && !strncmp("@@ -", patchline, 4)) {
+			int i;
+
+			i = sscanf(patchline+4, "%ld,%ld +%ld,%ld",
+					&oldline, &oldlen, &newline, &newlen);
+			if (i != 4)
+				bb_error_msg_and_die("corrupt hunk %d at %ld", TT.hunknum, TT.linenum);
+
+			TT.context = 0;
+			state = 2;
+
+			// If this is the first hunk, open the file.
+			if (TT.filein == -1) {
+				int oldsum, newsum, del = 0;
+				char *s, *name;
+
+ 				oldsum = oldline + oldlen;
+				newsum = newline + 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) && 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 <= 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) {
+		free(oldname);
+		free(newname);
+	}
+
+	return TT.exitval;
+}