Acorn RISC PD-CD 1/Acorn RISC PD-CD 1.iso/languages/c/gnu/diff/notes/diffbugs

Text File | 1991-05-03 | 8.4 KB | 319 lines

Path: cix!slxsys!ukc!mcsun!uunet!tut.cis.ohio-state.edu!unreplyable!garbage
From: [e-mail] (Matthew Dillon)
Newsgroups: gnu.utils.bug
Subject: BUG/COMPAT REPORT FOR DIFF-1.15.TAR
Message-ID: <[e-mail]>
Date: 16 Feb 91 10:54:02 GMT
Sender: [e-mail]
Distribution: gnu
Organization: GNUs Not Usenet
Lines: 261
Approved: [e-mail]


    Hello, I have a bug / compatibility report for you.  A few of the
    problems relate to a few unimplemented features in my C compiler,
    DICE, which you may or may not want to incorporate.  However,
    there are some genuine bugs / problems too.

    diff.h needs to include regex.h, forgot exactly where the problem
    was, some structure that was referenced but not defined due to
    no regex.h being included for that source module.

    diff.h is also missing an EXTERN keyword on one of the structures,
    yielding multiple-defined symbols on my machine.

    The changes to DIR.C relate to my compiler not being able to handle
    structural returns yet (but I'm working on it!  I just got dynamic
    stack extension working so at least I can run the GNU stack hogging
    programs now!)

    IO.C calculates a table index from a hash value via the mod operator
    without checking for possible negative results due to the signed
    int used for the hash value.  This could be a bug in my compiler, I
    cannot remember whether mod is supposed to be able to return
    negative numbers or not.  In anycase, it seemed dangerous.

    REGEX.C, a ?: construction has an expression return value of char *,
    but the second result is 0, which came back a warning on my compiler
    (again, this may be a non-bug since 0 == NULL by definition which is
    a valid pointer type)

    finally, I added #ifndef AMIGA's around the fork/wait code for
    the paginator.  While I can write unix support routines for everything
    else, fork() is a major problem on the amiga (instead, we spawn
    independant processes.  The amiga uses a linear address space).

    --

    In anycase, that's the bug report.  Thanks for diff & patch !

    P.S. double check that the indenting hasn't been screwed up due to
    the retabbing.

                    -Matt

    Matthew Dillon        [e-mail]
    891 Regal Rd.        uunet.uu.net!overload!dillon
    Berkeley, Ca. 94708
    USA

diff -c -w diff.old/diff.h diff/diff.h
*** diff.old/diff.h    Sun Jan 06 23:04:45 1991
--- diff/diff.h Fri Feb 15 16:38:06 1991
***************
*** 22,27 ****
--- 22,28 ----
  #include <stdio.h>
  #include <sys/types.h>
  #include <sys/stat.h>
+ #include "regex.h"

  #ifdef USG
  #include <time.h>
***************
*** 318,324 ****

  /* Describe the two files currently being compared.  */

! struct file_data files[2];

  /* Queue up one-line messages to be printed at the end,
     when -l is specified.  Each message is recorded with a `struct msg'.  */
--- 319,325 ----

  /* Describe the two files currently being compared.  */

! EXTERN struct file_data files[2];

  /* Queue up one-line messages to be printed at the end,
     when -l is specified.  Each message is recorded with a `struct msg'.  */
diff -c -w diff.old/dir.c diff/dir.c
*** diff.old/dir.c    Thu Nov 29 21:15:42 1990
--- diff/dir.c    Fri Feb 15 13:05:01 1991
***************
*** 31,37 ****
    char **files;            /* Sorted names of files in the dir */
  };

! static struct dirdata
  dir_sort (dirname, nonex)
       char *dirname;
       int nonex;
--- 31,37 ----
    char **files;        /* Sorted names of files in the dir */
  };

! static struct dirdata *
  dir_sort (dirname, nonex)
       char *dirname;
       int nonex;
***************
*** 38,44 ****
  {
    register DIR *reading;
    register struct direct *next;
!   struct dirdata dirdata;

    /* Address of block containing the files that are described.  */
    char **files;
--- 38,44 ----
  {
    register DIR *reading;
    register struct direct *next;
!   static struct dirdata dirdata;

    /* Address of block containing the files that are described.    */
    char **files;
***************
*** 53,59 ****
      {
    dirdata.length = 0;
    dirdata.files = 0;
!    return dirdata;
      }

    /* Open the directory and check for errors.  */
--- 53,59 ----
      {
    dirdata.length = 0;
    dirdata.files = 0;
!    return &dirdata;
      }

    /* Open the directory and check for errors.  */
***************
*** 62,68 ****
      {
    perror_with_name (dirname);
    dirdata.length = -1;
!    return dirdata;
      }

    /* Initialize the table of filenames.  */
--- 62,68 ----
      {
    perror_with_name (dirname);
    dirdata.length = -1;
!    return &dirdata;
      }

    /* Initialize the table of filenames.  */
***************
*** 101,107 ****
    dirdata.files = files;
    dirdata.length = files_index;

!   return dirdata;
  }

  /* Sort the files now in the table.  */
--- 101,107 ----
    dirdata.files = files;
    dirdata.length = files_index;

!   return &dirdata;
  }

  /* Sort the files now in the table.  */
***************
*** 144,151 ****
    int v1;

    /* Get sorted contents of both dirs.  */
!   data1 = dir_sort (name1, nonex1);
!   data2 = dir_sort (name2, nonex2);
    if (data1.length == -1 || data2.length == -1)
      {
    if (data1.length >= 0)
--- 144,151 ----
    int v1;

    /* Get sorted contents of both dirs.    */
!   data1 = *dir_sort (name1, nonex1);
!   data2 = *dir_sort (name2, nonex2);
    if (data1.length == -1 || data2.length == -1)
      {
    if (data1.length >= 0)
diff -c -w diff.old/io.c diff/io.c
*** diff.old/io.c    Thu Nov 29 21:15:43 1990
--- diff/io.c    Sat Feb 16 02:33:26 1991
***************
*** 549,555 ****

    /* Check through the appropriate bucket to see if there isn't already
       an equivalence class for this line. */
!   bucket = current->linbuf[n].hash % nbuckets;
    b = buckets[bucket];
    while (b)
      {
--- 549,555 ----

    /* Check through the appropriate bucket to see if there isn't already
       an equivalence class for this line. */
!   bucket = (current->linbuf[n].hash & 0x7FFFFFFF) % nbuckets;
    b = buckets[bucket];
    while (b)
      {
diff -c -w diff.old/regex.c diff/regex.c
*** diff.old/regex.c    Thu Nov 29 21:21:43 1990
--- diff/regex.c    Fri Feb 15 13:14:11 1991
***************
*** 857,863 ****
          BUFPUSH (stackp[-1]);
        }
          stackp -= 2;
!        fixup_jump = *stackp ? *stackp + bufp->buffer - 1 : 0;
        laststart = *--stackp + bufp->buffer;
          break;

--- 857,863 ----
          BUFPUSH (stackp[-1]);
        }
          stackp -= 2;
!          fixup_jump = *stackp ? *stackp + bufp->buffer - 1 : (char *)0;
          laststart = *--stackp + bufp->buffer;
          break;

diff -c -w diff.old/util.c diff/util.c
*** diff.old/util.c    Sun Jan 06 23:14:14 1991
--- diff/util.c Fri Feb 15 18:49:19 1991
***************
*** 131,136 ****
--- 131,137 ----

    if (paginate_flag)
      {
+ #ifndef AMIGA
    int pipes[2];
    int desc;

***************
*** 162,167 ****
--- 163,169 ----
      close (pipes[0]);
      outfile = fdopen (pipes[1], "w");
    }
+ #endif
      }
    else
      {
***************
*** 187,194 ****
--- 189,198 ----
  {
    if (outfile != stdout)
      {
+ #ifndef AMIGA
    fclose (outfile);
    wait (0);
+ #endif
      }
  }


Stuart A. Malone writes:

    First, the lack of a newline in the diff does not correspond to a lack
    of a newline on line b, but rather on line c, which is deceptive.

This is a bug in GNU DIFF 1.14.  Here is a patch.

    *** old/io.c    Tue Jul 31 14:49:55 1990
    --- new/io.c    Tue Jul 31 14:49:20 1990
    ***************
    *** 270,276 ****
            ++p;
          }

    !   if (output_style == OUTPUT_RCS && current->missing_newline)
          --current->linbuf[current->buffered_lines - 1].length;

        i = 0;
    --- 270,278 ----
            ++p;
          }

    !   if (output_style == OUTPUT_RCS
    !       && current->missing_newline
    !       && current->suffix_begin == current->buffer + current->buffered_chars)
          --current->linbuf[current->buffered_lines - 1].length;

        i = 0;


Malone also writes:

    Second, programs like RCS and ED expect such scripts to _always_ end in
    a newline, and execute the script incorrectly when they do not.  When
    producing scripts for RCS or ED, GNU DIFF should always end its output
    with a newline.

This is a bug in RCS and ED, not in DIFF.  RCS 4.2 and traditional ED do not
properly handle a file that ends in a character other than a newline.  I think
the next major release of RCS will work with such files.  Perhaps GNU ED will
work with them, too, although a minor enhancement to ED's command set is
probably needed.