Annotation of src/usr.bin/patch/patch.1, Revision 1.33
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1.33 ! jmc 22: .Dd $Mdocdate: June 22 2018 $
1.9 jmc 23: .Dt PATCH 1
24: .Os
25: .Sh NAME
26: .Nm patch
27: .Nd apply a diff file to an original
28: .Sh SYNOPSIS
29: .Nm patch
1.18 sobrado 30: .Bk -words
31: .Op Fl bCcEeflNnRstuv
32: .Op Fl B Ar backup-prefix
33: .Op Fl D Ar symbol
34: .Op Fl d Ar directory
35: .Op Fl F Ar max-fuzz
36: .Op Fl i Ar patchfile
37: .Op Fl o Ar out-file
38: .Op Fl p Ar strip-count
39: .Op Fl r Ar rej-name
40: .Op Fl V Cm t | nil | never
41: .Op Fl x Ar number
42: .Op Fl z Ar backup-ext
43: .Op Fl Fl posix
1.9 jmc 44: .Op Ar origfile Op Ar patchfile
1.18 sobrado 45: .Ek
1.9 jmc 46: .Nm patch
47: .Pf \*(Lt Ar patchfile
48: .Sh DESCRIPTION
49: .Nm
1.1 deraadt 50: will take a patch file containing any of the four forms of difference
51: listing produced by the
1.9 jmc 52: .Xr diff 1
53: program and apply those differences to an original file,
54: producing a patched version.
1.1 deraadt 55: If
1.9 jmc 56: .Ar patchfile
1.17 millert 57: is omitted, or is a hyphen, the patch will be read from the standard input.
1.9 jmc 58: .Pp
59: .Nm
1.23 jmc 60: will attempt to determine the type of the diff listing, unless overruled by a
1.9 jmc 61: .Fl c ,
62: .Fl e ,
63: .Fl n ,
1.1 deraadt 64: or
1.9 jmc 65: .Fl u
1.11 millert 66: option.
1.9 jmc 67: .Pp
1.17 millert 68: If the
69: .Ar patchfile
70: contains more than one patch,
1.9 jmc 71: .Nm
1.1 deraadt 72: will try to apply each of them as if they came from separate patch files.
73: This means, among other things, that it is assumed that the name of the file
1.17 millert 74: to patch must be determined for each diff listing, and that the garbage before
75: each diff listing will be examined for interesting things such as file names
76: and revision level (see the section on
77: .Sx Filename Determination
78: below).
1.9 jmc 79: .Pp
1.11 millert 80: The options are as follows:
1.9 jmc 81: .Bl -tag -width Ds
1.18 sobrado 82: .It Xo
83: .Fl B Ar backup-prefix ,
84: .Fl Fl prefix Ar backup-prefix
85: .Xc
86: Causes the next argument to be interpreted as a prefix to the backup file
87: name.
88: If this argument is specified, any argument to
89: .Fl z
90: will be ignored.
1.12 millert 91: .It Fl b , Fl Fl backup
92: Save a backup copy of the file before it is modified.
93: By default the original file is saved with a backup extension of
94: .Qq .orig
95: unless the file already has a numbered backup, in which case a numbered
96: backup is made.
97: This is equivalent to specifying
1.18 sobrado 98: .Qo Fl V Cm existing Qc .
1.22 jmc 99: This option is currently the default, unless
100: .Fl -posix
101: is specified.
1.32 zhuk 102: .It Fl C , Fl Fl check , Fl Fl dry-run
1.18 sobrado 103: Checks that the patch would apply cleanly, but does not modify anything.
1.9 jmc 104: .It Fl c , Fl Fl context
105: Forces
106: .Nm
1.1 deraadt 107: to interpret the patch file as a context diff.
1.18 sobrado 108: .It Xo
109: .Fl D Ar symbol ,
110: .Fl Fl ifdef Ar symbol
111: .Xc
1.9 jmc 112: Causes
113: .Nm
114: to use the
115: .Qq #ifdef...#endif
116: construct to mark changes.
1.1 deraadt 117: The argument following will be used as the differentiating symbol.
118: Note that, unlike the C compiler, there must be a space between the
1.9 jmc 119: .Fl D
1.1 deraadt 120: and the argument.
1.18 sobrado 121: .It Xo
122: .Fl d Ar directory ,
123: .Fl Fl directory Ar directory
124: .Xc
125: Causes
126: .Nm
1.21 jmc 127: to interpret the next argument as a directory,
128: and change working directory to it before doing anything else.
1.18 sobrado 129: .It Fl E , Fl Fl remove-empty-files
130: Causes
131: .Nm
132: to remove output files that are empty after the patches have been applied.
133: This option is useful when applying patches that create or remove files.
1.9 jmc 134: .It Fl e , Fl Fl ed
135: Forces
136: .Nm
137: to interpret the patch file as an
138: .Xr ed 1
139: script.
1.18 sobrado 140: .It Xo
141: .Fl F Ar max-fuzz ,
142: .Fl Fl fuzz Ar max-fuzz
143: .Xc
144: Sets the maximum fuzz factor.
145: This option only applies to context diffs, and causes
1.9 jmc 146: .Nm
1.18 sobrado 147: to ignore up to that many lines in looking for places to install a hunk.
148: Note that a larger fuzz factor increases the odds of a faulty patch.
149: The default fuzz factor is 2, and it may not be set to more than
150: the number of lines of context in the context diff, ordinarily 3.
1.9 jmc 151: .It Fl f , Fl Fl force
152: Forces
153: .Nm
1.1 deraadt 154: to assume that the user knows exactly what he or she is doing, and to not
1.9 jmc 155: ask any questions.
156: It assumes the following:
157: skip patches for which a file to patch can't be found;
158: patch files even though they have the wrong version for the
159: .Qq Prereq:
160: line in the patch;
161: and assume that patches are not reversed even if they look like they are.
1.1 deraadt 162: This option does not suppress commentary; use
1.9 jmc 163: .Fl s
1.1 deraadt 164: for that.
1.9 jmc 165: .It Xo
1.18 sobrado 166: .Fl i Ar patchfile ,
167: .Fl Fl input Ar patchfile
1.9 jmc 168: .Xc
1.15 millert 169: Causes the next argument to be interpreted as the input file name
170: (i.e. a patchfile).
1.9 jmc 171: .It Fl l , Fl Fl ignore-whitespace
172: Causes the pattern matching to be done loosely, in case the tabs and
1.1 deraadt 173: spaces have been munged in your input file.
174: Any sequence of whitespace in the pattern line will match any sequence
175: in the input file.
176: Normal characters must still match exactly.
177: Each line of the context must still match a line in the input file.
1.9 jmc 178: .It Fl N , Fl Fl forward
179: Causes
180: .Nm
1.1 deraadt 181: to ignore patches that it thinks are reversed or already applied.
182: See also
1.9 jmc 183: .Fl R .
1.18 sobrado 184: .It Fl n , Fl Fl normal
185: Forces
186: .Nm
187: to interpret the patch file as a normal diff.
188: .It Xo
189: .Fl o Ar out-file ,
190: .Fl Fl output Ar out-file
191: .Xc
1.9 jmc 192: Causes the next argument to be interpreted as the output file name.
193: .It Xo
1.18 sobrado 194: .Fl p Ar strip-count ,
195: .Fl Fl strip Ar strip-count
1.9 jmc 196: .Xc
197: Sets the pathname strip count,
198: which controls how pathnames found in the patch file are treated,
199: in case you keep your files in a different directory than the person who sent
1.1 deraadt 200: out the patch.
201: The strip count specifies how many slashes are to be stripped from
202: the front of the pathname.
203: (Any intervening directory names also go away.)
1.17 millert 204: For example, supposing the file name in the patch file was
1.9 jmc 205: .Pa /u/howard/src/blurfl/blurfl.c :
206: .Pp
207: Setting
208: .Fl p Ns Ar 0
209: gives the entire pathname unmodified.
210: .Pp
211: .Fl p Ns Ar 1
1.1 deraadt 212: gives
1.9 jmc 213: .Pp
214: .D1 Pa u/howard/src/blurfl/blurfl.c
215: .Pp
216: without the leading slash.
217: .Pp
218: .Fl p Ns Ar 4
1.1 deraadt 219: gives
1.9 jmc 220: .Pp
221: .D1 Pa blurfl/blurfl.c
222: .Pp
223: Not specifying
224: .Fl p
225: at all just gives you
226: .Pa blurfl.c ,
227: unless all of the directories in the leading path
228: .Pq Pa u/howard/src/blurfl
229: exist and that path is relative,
1.1 deraadt 230: in which case you get the entire pathname unmodified.
231: Whatever you end up with is looked for either in the current directory,
232: or the directory specified by the
1.9 jmc 233: .Fl d
1.11 millert 234: option.
1.9 jmc 235: .It Fl R , Fl Fl reverse
236: Tells
237: .Nm
1.1 deraadt 238: that this patch was created with the old and new files swapped.
239: (Yes, I'm afraid that does happen occasionally, human nature being what it
240: is.)
1.9 jmc 241: .Nm
1.1 deraadt 242: will attempt to swap each hunk around before applying it.
243: Rejects will come out in the swapped format.
244: The
1.9 jmc 245: .Fl R
1.11 millert 246: option will not work with ed diff scripts because there is too little
1.1 deraadt 247: information to reconstruct the reverse operation.
1.9 jmc 248: .Pp
1.1 deraadt 249: If the first hunk of a patch fails,
1.9 jmc 250: .Nm
1.1 deraadt 251: will reverse the hunk to see if it can be applied that way.
252: If it can, you will be asked if you want to have the
1.9 jmc 253: .Fl R
1.11 millert 254: option set.
1.1 deraadt 255: If it can't, the patch will continue to be applied normally.
256: (Note: this method cannot detect a reversed patch if it is a normal diff
257: and if the first command is an append (i.e. it should have been a delete)
258: since appends always succeed, due to the fact that a null context will match
259: anywhere.
260: Luckily, most patches add or change lines rather than delete them, so most
261: reversed normal diffs will begin with a delete, which will fail, triggering
262: the heuristic.)
1.9 jmc 263: .It Xo
1.18 sobrado 264: .Fl r Ar rej-name ,
265: .Fl Fl reject-file Ar rej-name
266: .Xc
267: Causes the next argument to be interpreted as the reject file name.
268: .It Xo
1.9 jmc 269: .Fl s , Fl Fl quiet ,
270: .Fl Fl silent
271: .Xc
272: Makes
273: .Nm
1.1 deraadt 274: do its work silently, unless an error occurs.
1.17 millert 275: .It Fl t , Fl Fl batch
276: Similar to
277: .Fl f ,
278: in that it suppresses questions, but makes some different assumptions:
279: skip patches for which a file to patch can't be found (the same as
280: .Fl f ) ;
281: skip patches for which the file has the wrong version for the
282: .Qq Prereq:
283: line in the patch;
284: and assume that patches are reversed if they look like they are.
1.9 jmc 285: .It Fl u , Fl Fl unified
286: Forces
287: .Nm
1.1 deraadt 288: to interpret the patch file as a unified context diff (a unidiff).
1.18 sobrado 289: .It Xo
290: .Fl V Cm t | nil | never ,
291: .Fl Fl version-control Cm t | nil | never
292: .Xc
1.9 jmc 293: Causes the next argument to be interpreted as a method for creating
294: backup file names.
295: The type of backups made can also be given in the
1.17 millert 296: .Ev PATCH_VERSION_CONTROL
297: or
1.9 jmc 298: .Ev VERSION_CONTROL
1.17 millert 299: environment variables, which are overridden by this option.
1.1 deraadt 300: The
1.9 jmc 301: .Fl B
1.1 deraadt 302: option overrides this option, causing the prefix to always be used for
303: making backup file names.
1.17 millert 304: The values of the
305: .Ev PATCH_VERSION_CONTROL
306: and
1.9 jmc 307: .Ev VERSION_CONTROL
1.17 millert 308: environment variables and the argument to the
1.9 jmc 309: .Fl V
310: option are like the GNU Emacs
311: .Dq version-control
312: variable; they also recognize synonyms that are more descriptive.
313: The valid values are (unique abbreviations are accepted):
314: .Bl -tag -width Ds -offset indent
1.18 sobrado 315: .It Cm t , numbered
1.1 deraadt 316: Always make numbered backups.
1.18 sobrado 317: .It Cm nil , existing
1.9 jmc 318: Make numbered backups of files that already have them,
319: simple backups of the others.
1.18 sobrado 320: .It Cm never , simple
1.1 deraadt 321: Always make simple backups.
1.9 jmc 322: .El
1.18 sobrado 323: .It Fl v , Fl Fl version
324: Causes
325: .Nm
326: to print out its revision header and patch level.
1.9 jmc 327: .It Xo
1.18 sobrado 328: .Fl x Ar number ,
329: .Fl Fl debug Ar number
1.9 jmc 330: .Xc
331: Sets internal debugging flags, and is of interest only to
332: .Nm
1.1 deraadt 333: patchers.
1.18 sobrado 334: .It Xo
335: .Fl z Ar backup-ext ,
336: .Fl Fl suffix Ar backup-ext
337: .Xc
1.12 millert 338: Causes the next argument to be interpreted as the backup extension, to be
339: used in place of
340: .Qq .orig .
1.17 millert 341: .It Fl Fl posix
342: Enables strict
1.24 jmc 343: .St -p1003.1-2008
1.17 millert 344: conformance, specifically:
345: .Bl -enum
346: .It
347: Backup files are not created unless the
348: .Fl b
349: option is specified.
350: .It
351: If unspecified, the file name used is the first of the old, new and
352: index files that exists.
353: .El
354: .El
355: .Ss Patch Application
356: .Nm
357: will try to skip any leading garbage, apply the diff,
358: and then skip any trailing garbage.
359: Thus you could feed an article or message containing a
360: diff listing to
361: .Nm patch ,
362: and it should work.
363: If the entire diff is indented by a consistent amount,
364: this will be taken into account.
365: .Pp
366: With context diffs, and to a lesser extent with normal diffs,
367: .Nm
368: can detect when the line numbers mentioned in the patch are incorrect,
369: and will attempt to find the correct place to apply each hunk of the patch.
370: As a first guess, it takes the line number mentioned for the hunk, plus or
371: minus any offset used in applying the previous hunk.
372: If that is not the correct place,
373: .Nm
374: will scan both forwards and backwards for a set of lines matching the context
375: given in the hunk.
376: First
377: .Nm
378: looks for a place where all lines of the context match.
379: If no such place is found, and it's a context diff, and the maximum fuzz factor
380: is set to 1 or more, then another scan takes place ignoring the first and last
381: line of context.
382: If that fails, and the maximum fuzz factor is set to 2 or more,
383: the first two and last two lines of context are ignored,
384: and another scan is made.
385: .Pq The default maximum fuzz factor is 2.
386: .Pp
387: If
388: .Nm
389: cannot find a place to install that hunk of the patch, it will put the hunk
390: out to a reject file, which normally is the name of the output file plus
391: .Qq .rej .
392: (Note that the rejected hunk will come out in context diff form whether the
393: input patch was a context diff or a normal diff.
394: If the input was a normal diff, many of the contexts will simply be null.)
395: The line numbers on the hunks in the reject file may be different than
396: in the patch file: they reflect the approximate location patch thinks the
397: failed hunks belong in the new file rather than the old one.
398: .Pp
399: As each hunk is completed, you will be told whether the hunk succeeded or
400: failed, and which line (in the new file)
401: .Nm
402: thought the hunk should go on.
403: If this is different from the line number specified in the diff,
404: you will be told the offset.
405: A single large offset MAY be an indication that a hunk was installed in the
406: wrong place.
407: You will also be told if a fuzz factor was used to make the match, in which
408: case you should also be slightly suspicious.
409: .Ss Filename Determination
410: If no original file is specified on the command line,
411: .Nm
412: will try to figure out from the leading garbage what the name of the file
413: to edit is.
414: When checking a prospective file name, pathname components are stripped
415: as specified by the
416: .Fl p
417: option and the file's existence and writability are checked relative
418: to the current working directory (or the directory specified by the
419: .Fl d
420: option).
421: .Pp
422: If the diff is a context or unified diff,
423: .Nm
424: is able to determine the old and new file names from the diff header.
425: For context diffs, the
426: .Dq old
427: file is specified in the line beginning with
428: .Qq ***
429: and the
430: .Dq new
431: file is specified in the line beginning with
432: .Qq --- .
433: For a unified diff, the
434: .Dq old
435: file is specified in the line beginning with
436: .Qq ---
437: and the
438: .Dq new
439: file is specified in the line beginning with
440: .Qq +++ .
441: If there is an
442: .Qq Index:
443: line in the leading garbage (regardless of the diff type),
444: .Nm
445: will use the file name from that line as the
446: .Dq index
447: file.
448: .Pp
449: .Nm
450: will choose the file name by performing the following steps, with the first
451: match used:
452: .Bl -enum
453: .It
454: If
455: .Nm
456: is operating in strict
1.24 jmc 457: .St -p1003.1-2008
1.17 millert 458: mode, the first of the
459: .Dq old ,
460: .Dq new
461: and
462: .Dq index
463: file names that exist is used.
464: Otherwise,
465: .Nm
466: will examine either the
467: .Dq old
468: and
469: .Dq new
470: file names or, for a non-context diff, the
471: .Dq index
472: file name, and choose the file name with the fewest path components,
473: the shortest basename, and the shortest total file name length (in that order).
474: .It
475: If no suitable file was found to patch, the patch file is a context or
476: unified diff, and the old file was zero length, the new file name is
477: created and used.
478: .It
479: If the file name still cannot be determined,
480: .Nm
481: will prompt the user for the file name to use.
1.9 jmc 482: .El
1.17 millert 483: .Pp
484: Additionally, if the leading garbage contains a
485: .Qq Prereq:\ \&
486: line,
487: .Nm
488: will take the first word from the prerequisites line (normally a version
489: number) and check the input file to see if that word can be found.
490: If not,
491: .Nm
492: will ask for confirmation before proceeding.
493: .Pp
494: The upshot of all this is that you should be able to say, while in a news
495: interface, the following:
496: .Pp
497: .Dl | patch -d /usr/src/local/blurfl
498: .Pp
499: and patch a file in the blurfl directory directly from the article containing
500: the patch.
501: .Ss Backup Files
502: By default, the patched version is put in place of the original, with
503: the original file backed up to the same name with the extension
504: .Qq .orig ,
505: or as specified by the
506: .Fl B ,
507: .Fl V ,
508: or
509: .Fl z
510: options.
511: The extension used for making backup files may also be specified in the
512: .Ev SIMPLE_BACKUP_SUFFIX
513: environment variable, which is overridden by the options above.
514: .Pp
515: If the backup file is a symbolic or hard link to the original file,
516: .Nm
517: creates a new backup file name by changing the first lowercase letter
518: in the last component of the file's name into uppercase.
519: If there are no more lowercase letters in the name,
520: it removes the first character from the name.
521: It repeats this process until it comes up with a
522: backup file that does not already exist or is not linked to the original file.
523: .Pp
524: You may also specify where you want the output to go with the
525: .Fl o
526: option; if that file already exists, it is backed up first.
527: .Ss Notes For Patch Senders
1.1 deraadt 528: There are several things you should bear in mind if you are going to
1.9 jmc 529: be sending out patches:
530: .Pp
531: First, you can save people a lot of grief by keeping a
532: .Pa patchlevel.h
533: file which is patched to increment the patch level as the first diff in the
1.1 deraadt 534: patch file you send out.
1.9 jmc 535: If you put a
536: .Qq Prereq:
537: line in with the patch, it won't let them apply
1.1 deraadt 538: patches out of order without some warning.
1.9 jmc 539: .Pp
1.17 millert 540: Second, make sure you've specified the file names right, either in a
1.9 jmc 541: context diff header, or with an
542: .Qq Index:
543: line.
1.1 deraadt 544: If you are patching something in a subdirectory, be sure to tell the patch
1.4 aaron 545: user to specify a
1.9 jmc 546: .Fl p
1.11 millert 547: option as needed.
1.9 jmc 548: .Pp
1.1 deraadt 549: Third, you can create a file by sending out a diff that compares a
550: null file to the file you want to create.
551: This will only work if the file you want to create doesn't exist already in
552: the target directory.
1.9 jmc 553: .Pp
1.1 deraadt 554: Fourth, take care not to send out reversed patches, since it makes people wonder
555: whether they already applied the patch.
1.9 jmc 556: .Pp
1.1 deraadt 557: Fifth, while you may be able to get away with putting 582 diff listings into
558: one file, it is probably wiser to group related patches into separate files in
559: case something goes haywire.
1.9 jmc 560: .Sh ENVIRONMENT
1.17 millert 561: .Bl -tag -width "PATCH_VERSION_CONTROL" -compact
562: .It Ev POSIXLY_CORRECT
563: When set,
564: .Nm
565: behaves as if the
566: .Fl Fl posix
567: option has been specified.
568: .It Ev SIMPLE_BACKUP_SUFFIX
569: Extension to use for backup file names instead of
570: .Qq .orig .
1.9 jmc 571: .It Ev TMPDIR
572: Directory to put temporary files in; default is
573: .Pa /tmp .
1.17 millert 574: .It Ev PATCH_VERSION_CONTROL
575: Selects when numbered backup files are made.
1.9 jmc 576: .It Ev VERSION_CONTROL
1.17 millert 577: Same as
578: .Ev PATCH_VERSION_CONTROL .
1.9 jmc 579: .El
580: .Sh FILES
1.17 millert 581: .Bl -tag -width "$TMPDIR/patch*" -compact
1.9 jmc 582: .It Pa $TMPDIR/patch*
1.17 millert 583: .Nm
584: temporary files
585: .It Pa /dev/tty
586: used to read input when
587: .Nm
588: prompts the user
1.9 jmc 589: .El
1.26 jmc 590: .Sh EXIT STATUS
591: The
592: .Nm
593: utility exits with one of the following values:
594: .Pp
595: .Bl -tag -width Ds -offset indent -compact
596: .It 0
597: Successful completion.
598: .It 1
599: One or more lines were written to a reject file.
600: .It \*(Gt1
601: An error occurred.
602: .El
603: .Pp
604: When applying a set of patches in a loop it behooves you to check this
605: exit status so you don't apply a later patch to a partially patched file.
1.9 jmc 606: .Sh DIAGNOSTICS
1.1 deraadt 607: Too many to list here, but generally indicative that
1.9 jmc 608: .Nm
1.1 deraadt 609: couldn't parse your patch file.
1.9 jmc 610: .Pp
611: The message
612: .Qq Hmm...
613: indicates that there is unprocessed text in the patch file and that
614: .Nm
1.1 deraadt 615: is attempting to intuit whether there is a patch in that text and, if so,
616: what kind of patch it is.
1.9 jmc 617: .Sh SEE ALSO
618: .Xr diff 1
1.19 jmc 619: .Sh STANDARDS
620: The
621: .Nm
622: utility is compliant with the
1.24 jmc 623: .St -p1003.1-2008
1.27 jmc 624: specification,
625: except as detailed above for the
1.22 jmc 626: .Fl -posix
1.27 jmc 627: option.
1.19 jmc 628: .Pp
629: The flags
1.25 jmc 630: .Op Fl BCEFfstVvxz
1.19 jmc 631: and
632: .Op Fl -posix
633: are extensions to that specification.
1.9 jmc 634: .Sh AUTHORS
1.13 millert 635: .An Larry Wall
1.9 jmc 636: with many other contributors.
637: .Sh CAVEATS
638: .Nm
1.1 deraadt 639: cannot tell if the line numbers are off in an ed script, and can only detect
1.9 jmc 640: bad line numbers in a normal diff when it finds a
641: .Qq change
642: or a
643: .Qq delete
644: command.
1.1 deraadt 645: A context diff using fuzz factor 3 may have the same problem.
646: Until a suitable interactive interface is added, you should probably do
647: a context diff in these cases to see if the changes made sense.
648: Of course, compiling without errors is a pretty good indication that the patch
649: worked, but not always.
1.9 jmc 650: .Pp
651: .Nm
1.1 deraadt 652: usually produces the correct results, even when it has to do a lot of
653: guessing.
654: However, the results are guaranteed to be correct only when the patch is
655: applied to exactly the same version of the file that the patch was
656: generated from.
1.9 jmc 657: .Sh BUGS
658: Could be smarter about partial matches, excessively deviant offsets and
1.1 deraadt 659: swapped code, but that would take an extra pass.
1.9 jmc 660: .Pp
661: Check patch mode
662: .Pq Fl C
1.3 espie 663: will fail if you try to check several patches in succession that build on
1.9 jmc 664: each other.
1.17 millert 665: The entire
1.9 jmc 666: .Nm
1.17 millert 667: code would have to be restructured to keep temporary files around so that it
668: can handle this situation.
1.9 jmc 669: .Pp
1.1 deraadt 670: If code has been duplicated (for instance with #ifdef OLDCODE ... #else ...
671: #endif),
1.9 jmc 672: .Nm
1.29 jmc 673: is incapable of patching both versions and, if it works at all, will likely
1.1 deraadt 674: patch the wrong one, and tell you that it succeeded to boot.
1.9 jmc 675: .Pp
1.1 deraadt 676: If you apply a patch you've already applied,
1.9 jmc 677: .Nm
1.1 deraadt 678: will think it is a reversed patch, and offer to un-apply the patch.
679: This could be construed as a feature.
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