patch 2.0 patch #8

[lwall at sdcrdcf.UUCP]

System: patch version 2.0
Patch #: 8
Priority: LOW
Subject: Short replacement part causes spurious "Out of sync" message.
From: hpl-opus!jewett (Bob Jewett)

Description:
	In a context diff, if the next-to-last hunk has a short replacement
	section (missing the last line or two of context) because the last
	hunk deletes everything from there to the end, patch reports that
	the lines of the pattern and replacement sections don't match up
	properly.  This doesn't happen very often, since few patches do
	deletions.  In fact, you're more likely to run across this bug when
	trying to apply a patch in reverse, when additions look like deletions.

	The problem was that the loop applying the patch needed two
	terminating conditions instead of one, since either the pattern
	part or the replacement part can run out first.  So much for
	structured programming.

Fix:	From rn, say "| patch -d DIR", where DIR is your patch source
	directory.  Outside of rn, say "cd DIR; patch <thisarticle".
	If you don't have the patch program, apply the following by hand,
	or get patch.

	If patch indicates that patchlevel is the wrong version, you may need
	to apply one or more previous patches, or the patch may already
	have been applied.  See the patchlevel.h file to find out what has or
	has not been applied.  In any event, don't continue with the patch.

	If you are missing previous patches they can be obtained from me:

	Larry Wall
	{allegra,burdvax,cbosgd,hplabs,ihnp4,sdcsvax}!sdcrdcf!lwall

	If you send a mail message of the following form it will greatly speed
	processing:

	Subject: Command
	@SH mailpatch PATH patch 2.0 LIST

	where PATH is a return path FROM ME TO YOU in bang notation, and LIST
	is the number of one or more patches you need, separated by spaces,
	commas, and/or hyphens.  Saying 35- says everything from 35 to the end.

Index: patchlevel.h
Prereq: 7
1c1
< #define PATCHLEVEL 7
---
> #define PATCHLEVEL 8
 
Index: patch.c
Prereq: 2.0.1.3
*** patch.c.old	Mon Feb 16 14:02:12 1987
*** patch.c	Mon Feb 16 14:02:18 1987
***************
*** 1,5
  char rcsid[] =
! 	"$Header: patch.c,v 2.0.1.3 87/01/30 22:45:50 lwall Exp $";
  
  /* patch - a program to apply diffs to original files
   *

--- 1,5 -----
  char rcsid[] =
! 	"$Header: patch.c,v 2.0.1.4 87/02/16 14:00:04 lwall Exp $";
  
  /* patch - a program to apply diffs to original files
   *
***************
*** 9,14
   * money off of it, or pretend that you wrote it.
   *
   * $Log:	patch.c,v $
   * Revision 2.0.1.3  87/01/30  22:45:50  lwall
   * Improved diagnostic on sync error.
   * Moved do_ed_script() to pch.c.

--- 9,17 -----
   * money off of it, or pretend that you wrote it.
   *
   * $Log:	patch.c,v $
+  * 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.
***************
*** 548,553
  #define IN_ELSE 3
      Reg4 int def_state = OUTSIDE;
      Reg5 bool R_do_defines = do_defines;
  
      where--;
      while (pch_char(new) == '=' || pch_char(new) == '\n')

--- 551,557 -----
  #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')
***************
*** 570,575
  	    last_frozen_line++;
  	    old++;
  	}
  	else if (pch_char(new) == '+') {
  	    copy_till(where + old - 1);
  	    if (R_do_defines) {

--- 574,581 -----
  	    last_frozen_line++;
  	    old++;
  	}
+ 	else if (new > pat_end)
+ 	    break;
  	else if (pch_char(new) == '+') {
  	    copy_till(where + old - 1);
  	    if (R_do_defines) {
***************
*** 629,635
  	    }
  	}
      }
!     if (new <= pch_end() && pch_char(new) == '+') {
  	copy_till(where + old - 1);
  	if (R_do_defines) {
  	    if (def_state == OUTSIDE) {

--- 635,641 -----
  	    }
  	}
      }
!     if (new <= pat_end && pch_char(new) == '+') {
  	copy_till(where + old - 1);
  	if (R_do_defines) {
  	    if (def_state == OUTSIDE) {
***************
*** 641,647
  		def_state = IN_ELSE;
  	    }
  	}
! 	while (new <= pch_end() && pch_char(new) == '+') {
  	    fputs(pfetch(new), ofp);
  	    new++;
  	}

--- 647,653 -----
  		def_state = IN_ELSE;
  	    }
  	}
! 	while (new <= pat_end && pch_char(new) == '+') {
  	    fputs(pfetch(new), ofp);
  	    new++;
  	}