char rcsid[] =
      "$Header: patch.c,v 2.0.1.6 88/06/22 20:46:39 lwall Locked $";

/* patch - a program to apply diffs to original files
 *
 * Copyright 1986, Larry Wall
 *
 * This program may be copied as long as you don't try to make any
 * money off of it, or pretend that you wrote it.
 *
 * $Log:        patch.c,v $
 * Revision 2.0.1.6  88/06/22  20:46:39  lwall
 * patch12: rindex() wasn't declared
 *
 * Revision 2.0.1.5  88/06/03  15:09:37  lwall
 * patch10: exit code improved.
 * patch10: better support for non-flexfilenames.
 *
 * Revision 2.0.1.4  87/02/16  14:00:04  lwall
 * Short replacement caused spurious "Out of sync" message.
 *
 * Revision 2.0.1.3  87/01/30  22:45:50  lwall
 * Improved diagnostic on sync error.
 * Moved do_ed_script() to pch.c.
 *
 * Revision 2.0.1.2  86/11/21  09:39:15  lwall
 * Fuzz factor caused offset of installed lines.
 *
 * Revision 2.0.1.1  86/10/29  13:10:22  lwall
 * Backwards search could terminate prematurely.
 *
 * Revision 2.0  86/09/17  15:37:32  lwall
 * Baseline for netwide release.
 *
 * Revision 1.5  86/08/01  20:53:24  lwall
 * Changed some %d's to %ld's.
 * Linted.
 *
 * Revision 1.4  86/08/01  19:17:29  lwall
 * Fixes for machines that can't vararg.
 * Added fuzz factor.
 * Generalized -p.
 * General cleanup.
 *
 * 85/08/15 van%ucbmonet@berkeley
 * Changes for 4.3bsd diff -c.
 *
 * Revision 1.3  85/03/26  15:07:43  lwall
 * Frozen.
 *
 * Revision 1.2.1.9  85/03/12  17:03:35  lwall
 * Changed pfp->_file to fileno(pfp).
 *
 * Revision 1.2.1.8  85/03/12  16:30:43  lwall
 * Check i_ptr and i_womp to make sure they aren't null before freeing.
 * Also allow ed output to be suppressed.
 *
 * Revision 1.2.1.7  85/03/12  15:56:13  lwall
 * Added -p option from jromine@uci-750a.
 *
 * Revision 1.2.1.6  85/03/12  12:12:51  lwall
 * Now checks for normalness of file to patch.
 *
 * Revision 1.2.1.5  85/03/12  11:52:12  lwall
 * Added -D (#ifdef) option from joe@fluke.
 *
 * Revision 1.2.1.4  84/12/06  11:14:15  lwall
 * Made smarter about SCCS subdirectories.
 *
 * Revision 1.2.1.3  84/12/05  11:18:43  lwall
 * Added -l switch to do loose string comparison.
 *
 * Revision 1.2.1.2  84/12/04  09:47:13  lwall
 * Failed hunk count not reset on multiple patch file.
 *
 * Revision 1.2.1.1  84/12/04  09:42:37  lwall
 * Branch for sdcrdcf changes.
 *
 * Revision 1.2  84/11/29  13:29:51  lwall
 * Linted.  Identifiers uniqified.  Fixed i_ptr malloc() bug.  Fixed
 * multiple calls to mktemp().  Will now work on machines that can only
 * read 32767 chars.  Added -R option for diffs with new and old swapped.
 * Various cosmetic changes.
 *
 * Revision 1.1  84/11/09  17:03:58  lwall
 * Initial revision
 *
 */

#include "INTERN.h"
#include "common.h"
#include "EXTERN.h"
#include "version.h"
#include "util.h"
#include "pch.h"
#include "inp.h"

/* procedures */

void reinitialize_almost_everything();
void get_some_switches();
LINENUM locate_hunk();
void abort_hunk();
void apply_hunk();
void init_output();
void init_reject();
void copy_till();
void spew_output();
void dump_line();
bool patch_match();
bool similar();
void re_input();
void my_exit();

/* Apply a set of diffs as appropriate. */

main(argc,argv)
int argc;
char **argv;
{
    LINENUM where;
    LINENUM newwhere;
    LINENUM fuzz;
    LINENUM mymaxfuzz;
    int hunk = 0;
    int failed = 0;
    int failtotal = 0;
    int i;


#ifdef AMIGA  /* set up heapmem.o for Manx */
   extern long _Heapsize;

   _Heapsize = 60000;   /* works only on expanded machines, probably. */
#endif

    setbuf(stderr, serrbuf);
    for (i = 0; i<MAXFILEC; i++)
        filearg[i] = Nullch;
    Mktemp(TMPOUTNAME);
    Mktemp(TMPINNAME);
    Mktemp(TMPREJNAME);
    Mktemp(TMPPATNAME);

    /* parse switches */
    Argc = argc;
    Argv = argv;
    get_some_switches();

    /* make sure we clean up /tmp in case of disaster */
    set_signals(0);

    for (
        open_patch_file(filearg[1]);
        there_is_another_patch();
        reinitialize_almost_everything()
    ) {                                 /* for each patch in patch file */

        if (outname == Nullch)
            outname = savestr(filearg[0]);

        /* initialize the patched file */
        if (!skip_rest_of_patch)
            init_output(TMPOUTNAME);

        /* for ed script just up and do it and exit */
        if (diff_type == ED_DIFF) {
            do_ed_script();
            continue;
        }

        /* initialize reject file */
        init_reject(TMPREJNAME);

        /* find out where all the lines are */
        if (!skip_rest_of_patch)
            scan_input(filearg[0]);

        /* from here on, open no standard i/o files, because malloc */
        /* might misfire and we can't catch it easily */

        /* apply each hunk of patch */
        hunk = 0;
        failed = 0;
        out_of_mem = FALSE;
        while (another_hunk()) {
            hunk++;
            fuzz = Nulline;
            mymaxfuzz = pch_context();
            if (maxfuzz < mymaxfuzz)
                mymaxfuzz = maxfuzz;
            if (!skip_rest_of_patch) {
                do {
                    where = locate_hunk(fuzz);
                    if (hunk == 1 && where == Nulline && !force) {
                                                /* dwim for reversed patch? */
                        if (!pch_swap()) {
                            if (fuzz == Nulline)
                                say1(
"Not enough memory to try swapped hunk!  Assuming unswapped.\n");
                            continue;
                        }
                        reverse = !reverse;
                        where = locate_hunk(fuzz);  /* try again */
                        if (where == Nulline) {     /* didn't find it swapped */
                            if (!pch_swap())         /* put it back to normal */
                                fatal1("Lost hunk on alloc error!\n");
                            reverse = !reverse;
                        }
                        else if (noreverse) {
                            if (!pch_swap())         /* put it back to normal */
                                fatal1("Lost hunk on alloc error!\n");
                            reverse = !reverse;
                            say1(
"Ignoring previously applied (or reversed) patch.\n");
                            skip_rest_of_patch = TRUE;
                        }
                        else {
                            ask3(
"%seversed (or previously applied) patch detected!  %s -R? [y] ",
                                reverse ? "R" : "Unr",
                                reverse ? "Assume" : "Ignore");
                            if (*buf == 'n') {
                                ask1("Apply anyway? [n] ");
                                if (*buf != 'y')
                                    skip_rest_of_patch = TRUE;
                                where = Nulline;
                                reverse = !reverse;
                                if (!pch_swap())  /* put it back to normal */
                                    fatal1("Lost hunk on alloc error!\n");
                            }
                        }
                    }
                } while (!skip_rest_of_patch && where == Nulline &&
                    ++fuzz <= mymaxfuzz);

                if (skip_rest_of_patch) {               /* just got decided */
                    Fclose(ofp);
                    ofp = Nullfp;
                }
            }

            newwhere = pch_newfirst() + last_offset;
            if (skip_rest_of_patch) {
                abort_hunk();
                failed++;
                if (verbose)
                    say3("Hunk #%d ignored at %ld.\n", hunk, newwhere);
            }
            else if (where == Nulline) {
                abort_hunk();
                failed++;
                if (verbose)
                    say3("Hunk #%d failed at %ld.\n", hunk, newwhere);
            }
            else {
                apply_hunk(where);
                if (verbose) {
                    say3("Hunk #%d succeeded at %ld", hunk, newwhere);
                    if (fuzz)
                        say2(" with fuzz %ld", fuzz);
                    if (last_offset)
                        say3(" (offset %ld line%s)",
                            last_offset, last_offset==1L?"":"s");
                    say1(".\n");
                }
            }
        }

        if (out_of_mem && using_plan_a) {
            Argc = Argc_last;
            Argv = Argv_last;
            say1("\n\nRan out of memory using Plan A--trying again...\n\n");
            Fclose(ofp);     /* fixed -- elg. */
            Fclose(rejfp);
            continue;
        }

        assert(hunk);

        /* finish spewing out the new file */
        if (!skip_rest_of_patch)
            spew_output();

        /* and put the output where desired */
        ignore_signals();
        if (!skip_rest_of_patch) {
            if (move_file(TMPOUTNAME, outname) < 0) {
                toutkeep = TRUE;
                chmod(TMPOUTNAME, filemode);
            }
            else
                chmod(outname, filemode);
        }
        Fclose(rejfp);
        rejfp = Nullfp;
        if (failed) {
            failtotal += failed;
            if (!*rejname) {
                Strcpy(rejname, outname);
#ifndef FLEXFILENAMES
                {
                    char *rindex();
                    char *s = rindex(rejname,'/');

                    if (!s)
                        s = rejname;
                    if (strlen(s) > 13)
                        if (s[12] == '.')       /* try to preserve difference */
                            s[12] = s[13];      /* between .h, .c, .y, etc. */
                        s[13] = '\0';
                }
#endif
                Strcat(rejname, REJEXT);
            }
            if (skip_rest_of_patch) {
                say4("%d out of %d hunks ignored--saving rejects to %s\n",
                    failed, hunk, rejname);
            }
            else {
                say4("%d out of %d hunks failed--saving rejects to %s\n",
                    failed, hunk, rejname);
            }
            if (move_file(TMPREJNAME, rejname) < 0)
                trejkeep = TRUE;
        }
        set_signals(1);
    }
    my_exit(failtotal);
}

/* Prepare to find the next patch to do in the patch file. */

void
reinitialize_almost_everything()
{
    re_patch();
    re_input();

    input_lines = 0;
    last_frozen_line = 0;

    filec = 0;
    if (filearg[0] != Nullch && !out_of_mem) {
        free(filearg[0]);
        filearg[0] = Nullch;
    }

    if (outname != Nullch) {
        free(outname);
        outname = Nullch;
    }

    last_offset = 0;

    diff_type = 0;

    if (revision != Nullch) {
        free(revision);
        revision = Nullch;
    }

    reverse = FALSE;
    skip_rest_of_patch = FALSE;

    get_some_switches();

    if (filec >= 2)
        fatal1("You may not change to a different patch file.\n");
}

/* Process switches and filenames up to next '+' or end of list. */

void
get_some_switches()
{
    Reg1 char *s;

    rejname[0] = '\0';
    Argc_last = Argc;
    Argv_last = Argv;
    if (!Argc)
        return;
    for (Argc--,Argv++; Argc; Argc--,Argv++) {
        s = Argv[0];
        if (strEQ(s, "+")) {
            return;                     /* + will be skipped by for loop */
        }
        if (*s != '-' || !s[1]) {
            if (filec == MAXFILEC)
                fatal1("Too many file arguments.\n");
            filearg[filec++] = savestr(s);
        }
        else {
            switch (*++s) {
            case 'b':
                origext = savestr(Argv[1]);
                Argc--,Argv++;
                break;
            case 'B':
                origprae = savestr(Argv[1]);
                Argc--,Argv++;
                break;
            case 'c':
                diff_type = CONTEXT_DIFF;
                break;
            case 'd':
                if (!*++s) {
                    Argc--,Argv++;
                    s = Argv[0];
                }
      /* note that I have written chdir for the Amiga now. */
                if (chdir(s) < 0)
                    fatal2("Can't cd to %s.\n", s);
                break;
            case 'D':
                do_defines = TRUE;
                if (!*++s) {
                    Argc--,Argv++;
                    s = Argv[0];
                }
                if (!isalpha(*s))
                    fatal1("Argument to -D not an identifier.\n");
                Sprintf(if_defined, "#ifdef %s\n", s);
                Sprintf(not_defined, "#ifndef %s\n", s);
                Sprintf(end_defined, "#endif /* %s */\n", s);
                break;
            case 'e':
                diff_type = ED_DIFF;
                break;
            case 'f':
                force = TRUE;
                break;
            case 'F':
                if (*++s == '=')
                    s++;
                maxfuzz = atoi(s);
                break;
            case 'l':
                canonicalize = TRUE;
                break;
            case 'n':
                diff_type = NORMAL_DIFF;
                break;
            case 'N':
                noreverse = TRUE;
                break;
            case 'o':
                outname = savestr(Argv[1]);
                Argc--,Argv++;
                break;
            case 'p':
                if (*++s == '=')
                    s++;
                strippath = atoi(s);
                break;
            case 'r':
                Strcpy(rejname, Argv[1]);
                Argc--,Argv++;
                break;
            case 'R':
                reverse = TRUE;
                break;
            case 's':
                verbose = FALSE;
                break;
            case 'S':
                skip_rest_of_patch = TRUE;
                break;
            case 'v':
                version();
                break;
#ifdef DEBUGGING
            case 'x':
                debug = atoi(s+1);
                break;
#endif
            default:
                fatal2("Unrecognized switch: %s\n", Argv[0]);
            }
        }
    }
}

/* Attempt to find the right place to apply this hunk of patch. */

LINENUM
locate_hunk(fuzz)
LINENUM fuzz;
{
    Reg1 LINENUM first_guess = pch_first() + last_offset;
    Reg2 LINENUM offset;
    LINENUM pat_lines = pch_ptrn_lines();
    Reg3 LINENUM max_pos_offset = input_lines - first_guess
                                - pat_lines + 1;
    Reg4 LINENUM max_neg_offset = first_guess - last_frozen_line - 1
                                + pch_context();

    if (!pat_lines)                     /* null range matches always */
        return first_guess;
    if (max_neg_offset >= first_guess)  /* do not try lines < 0 */
        max_neg_offset = first_guess - 1;
    if (first_guess <= input_lines && patch_match(first_guess, Nulline, fuzz))
        return first_guess;
    for (offset = 1; ; offset++) {
        Reg5 bool check_after = (offset <= max_pos_offset);
      Reg6 bool check_before = (offset <= max_neg_offset);

        if (check_after && patch_match(first_guess, offset, fuzz)) {
#ifdef DEBUGGING
            if (debug & 1)
                say3("Offset changing from %ld to %ld\n", last_offset, offset);
#endif
            last_offset = offset;
            return first_guess+offset;
        }
        else if (check_before && patch_match(first_guess, -offset, fuzz)) {
#ifdef DEBUGGING
            if (debug & 1)
                say3("Offset changing from %ld to %ld\n", last_offset, -offset);
#endif
            last_offset = -offset;
            return first_guess-offset;
        }
        else if (!check_before && !check_after)
            return Nulline;
    }
}

/* We did not find the pattern, dump out the hunk so they can handle it. */

void
abort_hunk()
{
    Reg1 LINENUM i;
    Reg2 LINENUM pat_end = pch_end();
    /* add in last_offset to guess the same as the previous successful hunk */
    LINENUM oldfirst = pch_first() + last_offset;
    LINENUM newfirst = pch_newfirst() + last_offset;
    LINENUM oldlast = oldfirst + pch_ptrn_lines() - 1;
    LINENUM newlast = newfirst + pch_repl_lines() - 1;
    char *stars = (diff_type == NEW_CONTEXT_DIFF ? " ****" : "");
    char *minuses = (diff_type == NEW_CONTEXT_DIFF ? " ----" : " -----");

    fprintf(rejfp, "***************\n");
    for (i=0; i<=pat_end; i++) {
        switch (pch_char(i)) {
        case '*':
            if (oldlast < oldfirst)
                fprintf(rejfp, "*** 0%s\n", stars);
            else if (oldlast == oldfirst)
                fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
            else
                fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst, oldlast, stars);
            break;
        case '=':
            if (newlast < newfirst)
                fprintf(rejfp, "--- 0%s\n", minuses);
            else if (newlast == newfirst)
                fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
            else
                fprintf(rejfp, "--- %ld,%ld%s\n", newfirst, newlast, minuses);
            break;
        case '\n':
            fprintf(rejfp, "%s", pfetch(i));
            break;
        case ' ': case '-': case '+': case '!':
            fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
            break;
        default:
            say1("Fatal internal error in abort_hunk().\n");
            abort();
        }
    }
}

/* We found where to apply it (we hope), so do it. */

void
apply_hunk(where)
LINENUM where;
{
    Reg1 LINENUM old = 1;
    Reg2 LINENUM lastline = pch_ptrn_lines();
    Reg3 LINENUM new = lastline+1;
#define OUTSIDE 0
#define IN_IFNDEF 1
#define IN_IFDEF 2
#define IN_ELSE 3
    Reg4 int def_state = OUTSIDE;
    Reg5 bool R_do_defines = do_defines;
    Reg6 LINENUM pat_end = pch_end();

    where--;
    while (pch_char(new) == '=' || pch_char(new) == '\n')
        new++;

    while (old <= lastline) {
        if (pch_char(old) == '-') {
            copy_till(where + old - 1);
            if (R_do_defines) {
                if (def_state == OUTSIDE) {
                    fputs(not_defined, ofp);
                    def_state = IN_IFNDEF;
                }
                else if (def_state == IN_IFDEF) {
                    fputs(else_defined, ofp);
                    def_state = IN_ELSE;
                }
                fputs(pfetch(old), ofp);
            }
            last_frozen_line++;
            old++;
        }
        else if (new > pat_end)
            break;
        else if (pch_char(new) == '+') {
            copy_till(where + old - 1);
            if (R_do_defines) {
                if (def_state == IN_IFNDEF) {
                    fputs(else_defined, ofp);
                    def_state = IN_ELSE;
                }
                else if (def_state == OUTSIDE) {
                    fputs(if_defined, ofp);
                    def_state = IN_IFDEF;
                }
            }
            fputs(pfetch(new), ofp);
            new++;
        }
        else {
            if (pch_char(new) != pch_char(old)) {
                say3("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
                    pch_hunk_beg() + old,
                    pch_hunk_beg() + new);
#ifdef DEBUGGING
                say3("oldchar = '%c', newchar = '%c'\n",
                    pch_char(old), pch_char(new));
#endif
                my_exit(1);
            }
            if (pch_char(new) == '!') {
                copy_till(where + old - 1);
                if (R_do_defines) {
                   fputs(not_defined, ofp);
                   def_state = IN_IFNDEF;
                }
                while (pch_char(old) == '!') {
                    if (R_do_defines) {
                        fputs(pfetch(old), ofp);
                    }
                    last_frozen_line++;
                    old++;
                }
                if (R_do_defines) {
                    fputs(else_defined, ofp);
                    def_state = IN_ELSE;
                }
                while (pch_char(new) == '!') {
                    fputs(pfetch(new), ofp);
                    new++;
                }
                if (R_do_defines) {
                    fputs(end_defined, ofp);
                    def_state = OUTSIDE;
                }
            }
            else {
                assert(pch_char(new) == ' ');
                old++;
                new++;
            }
        }
    }
    if (new <= pat_end && pch_char(new) == '+') {
        copy_till(where + old - 1);
        if (R_do_defines) {
            if (def_state == OUTSIDE) {
                fputs(if_defined, ofp);
                def_state = IN_IFDEF;
            }
            else if (def_state == IN_IFNDEF) {
                fputs(else_defined, ofp);
                def_state = IN_ELSE;
            }
        }
        while (new <= pat_end && pch_char(new) == '+') {
            fputs(pfetch(new), ofp);
            new++;
        }
    }
    if (R_do_defines && def_state != OUTSIDE) {
        fputs(end_defined, ofp);
    }
}


/* Open the new file. */

void
init_output(name)
char *name;
{
    ofp = fopen(name, "w");
    if (ofp == Nullfp)
        fatal2("patch init output: can't create %s.\n", name);
}

/* Open a file to put hunks we can't locate. */

void
init_reject(name)
char *name;
{
    rejfp = fopen(name, "w");
    if (rejfp == Nullfp)
        fatal2("patch init reject: can't create %s.\n", name);
}

/* Copy input file to output, up to wherever hunk is to be applied. */

void
copy_till(lastline)
Reg1 LINENUM lastline;
{
    Reg2 LINENUM R_last_frozen_line = last_frozen_line;

    if (R_last_frozen_line > lastline)
        say1("patch: misordered hunks! output will be garbled.\n");
    while (R_last_frozen_line < lastline) {
        dump_line(++R_last_frozen_line);
    }
    last_frozen_line = R_last_frozen_line;
}

/* Finish copying the input file to the output file. */

void
spew_output()
{
#ifdef DEBUGGING
    if (debug & 256)
        say3("il=%ld lfl=%ld\n",input_lines,last_frozen_line);
#endif
    if (input_lines)
        copy_till(input_lines);         /* dump remainder of file */
    Fclose(ofp);
    ofp = Nullfp;
}

/* Copy one line from input to output. */

void
dump_line(line)
LINENUM line;
{
    Reg1 char *s;
    Reg2 char R_newline = '\n';

    /* Note: string is not null terminated. */
    for (s=ifetch(line, 0); putc(*s, ofp) != R_newline; s++) ;
}

/* Does the patch pattern match at line base+offset? */

bool
patch_match(base, offset, fuzz)
LINENUM base;
LINENUM offset;
LINENUM fuzz;
{
    Reg1 LINENUM pline = 1 + fuzz;
    Reg2 LINENUM iline;
    Reg3 LINENUM pat_lines = pch_ptrn_lines() - fuzz;

    for (iline=base+offset+fuzz; pline <= pat_lines; pline++,iline++) {
        if (canonicalize) {
            if (!similar(ifetch(iline, (offset >= 0)),
                         pfetch(pline),
                         pch_line_len(pline) ))
                return FALSE;
        }
        else if (strnNE(ifetch(iline, (offset >= 0)),
                   pfetch(pline),
                   pch_line_len(pline) ))
            return FALSE;
    }
    return TRUE;
}

/* Do two lines match with canonicalized white space? */

bool
similar(a,b,len)
Reg1 char *a;
Reg2 char *b;
Reg3 int len;
{
    while (len) {
        if (isspace(*b)) {              /* whitespace (or \n) to match? */
            if (!isspace(*a))           /* no corresponding whitespace? */
                return FALSE;
            while (len && isspace(*b) && *b != '\n')
                b++,len--;              /* skip pattern whitespace */
            while (isspace(*a) && *a != '\n')
                a++;                    /* skip target whitespace */
            if (*a == '\n' || *b == '\n')
                return (*a == *b);      /* should end in sync */
        }
        else if (*a++ != *b++)          /* match non-whitespace chars */
            return FALSE;
        else
            len--;                      /* probably not necessary */
    }
    return TRUE;                        /* actually, this is not reached */
                                        /* since there is always a \n */
}

/* Exit with cleanup. */

void
my_exit(status)
int status;
{

/* ah hah! With AmyDos everything must be closed! */
#ifdef AMIGA
    int i;
    extern short _numdev;
    for (i=3;i<_numdev;i++)
        close(i);
#endif

    Unlink(TMPINNAME);
    if (!toutkeep) {
        Unlink(TMPOUTNAME);
    }
    if (!trejkeep) {
        Unlink(TMPREJNAME);
    }
    Unlink(TMPPATNAME);
    exit(status);
}