patch: replace it with toybox's implementation

Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 306 insertions, 0 deletions

diff --git a/editors/patch_bbox.c b/editors/patch_bbox.c
new file mode 100644
index 000000000..62477af16
--- /dev/null
+++ b/editors/patch_bbox.c
@@ -0,0 +1,306 @@
+/* vi: set sw=4 ts=4: */
+/*
+ *  busybox patch applet to handle the unified diff format.
+ *  Copyright (C) 2003 Glenn McGrath
+ *
+ *  Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ *
+ *  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
+                        ;
+                applet_long_options = patch_longopts;
+#endif
+                /* -f,-E,-g are ignored */
+                opt = getopt32(argv, "p:i:RN""fEg:", &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, "@@ -%d,%d +%d,%d", &src_beg_line, &src_last_line, &dst_beg_line, &dst_last_line) < 3)
+                         && (sscanf(patch_line, "@@ -%d +%d,%d", &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;
+}