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 000000000..f1e0de6cd
--- /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;
+}