Fixed non-conflict errors that occur when changes made to the local f…

…iles are

the same as the changes made in the repository.  This is often seen by
people with remote CVS trees that have applied their local patches to the
master site.  a 'cvs update' will show bogus conflicts.

Obtained from: CVS mailing list, Stig<[email protected]>

In diffutils 2.6 and 2.7, diff3 -A complains about identical overlapping
changes.  They're different from the ancestor but not from each other...
Why bother?  The patch below fixes this nonsense and preserves [B]ackwards
compatiblity with the -B flag (also --show-bogus-conflicts).

    Party on...
    Stig

gnu/usr.bin/diff/diff3.c

@@ -163,7 +163,9 @@ static int simple_only;
 /* If nonzero, do not output information for non-overlapping diffs.  */
 static int overlap_only;
 
-/* If nonzero, show information for DIFF_2ND diffs.  */
+/* If nonzero, show information for 3_way and DIFF_2ND diffs.  
+   1= show 2nd only when 1st and 3rd differ
+   2= show 2nd when DIFF_2ND (1 and 3 have same change relative to 2) */
 static int show_2nd;
 
 /* If nonzero, include `:wq' at the end of the script
@@ -204,6 +206,7 @@ static struct option const longopts[] =
 {
   {"text", 0, 0, 'a'},
   {"show-all", 0, 0, 'A'},
+  {"show-bogus-conflicts", 0, 0, 'B'},
   {"ed", 0, 0, 'e'},
   {"show-overlap", 0, 0, 'E'},
   {"label", 1, 0, 'L'},
@@ -242,15 +245,18 @@ main (argc, argv)
 
   argv0 = argv[0];
 
-  while ((c = getopt_long (argc, argv, "aeimvx3AEL:TX", longopts, 0)) != EOF)
+  while ((c = getopt_long (argc, argv, "aeimvx3ABEL:TX", longopts, 0)) != EOF)
     {
       switch (c)
 	{
 	case 'a':
 	  always_text = 1;
 	  break;
+	case 'B':
+	  ++show_2nd;
+	  /* Falls through */
 	case 'A':
-	  show_2nd = 1;
+	  ++show_2nd;
 	  flagging = 1;
 	  incompat++;
 	  break;
@@ -401,11 +407,12 @@ usage (status)
   printf ("\
 Usage: %s [options] my-file older-file your-file\n\
 Options:\n\
-	[-exAEX3aTv] [-i|-m] [-L label1 [-L label2 [-L label3]]]\n\
+	[-exABEX3aTv] [-i|-m] [-L label1 [-L label2 [-L label3]]]\n\
 	[--easy-only] [--ed] [--help] [--initial-tab]\n\
 	[--label=label1 [--label=label2 [--label=label3]]] [--merge]\n\
-	[--overlap-only] [--show-all] [--show-overlap] [--text] [--version]\n\
-	Only one of [exAEX3] is allowed\n", argv0);
+	[--overlap-only] [--show-all] [ --show-bogus-conflicts ]\n\
+	[--show-overlap] [--text] [--version]\n\
+	Only one of [exABEX3] is allowed\n", argv0);
   exit (status);
 }
 
@@ -1423,7 +1430,7 @@ output_diff3_edscript (outputfile, diff, mapping, rev_mapping,
       switch (type)
 	{
 	default: continue;
-	case DIFF_2ND: if (!show_2nd) continue; conflict = 1; break;
+	case DIFF_2ND: if (show_2nd < 2) continue; conflict = 1; break;
 	case DIFF_3RD: if (overlap_only) continue; conflict = 0; break;
 	case DIFF_ALL: if (simple_only) continue; conflict = flagging; break;
 	}
@@ -1552,7 +1559,7 @@ output_diff3_merge (infile, outputfile, diff, mapping, rev_mapping,
       switch (type)
 	{
 	default: continue;
-	case DIFF_2ND: if (!show_2nd) continue; conflict = 1; break;
+	case DIFF_2ND: if (show_2nd < 2) continue; conflict = 1; break;
 	case DIFF_3RD: if (overlap_only) continue; conflict = 0; break;
 	case DIFF_ALL: if (simple_only) continue; conflict = flagging;
 	  format_2nd = "||||||| %s\n";

gnu/usr.bin/diff3/diff3.1

@@ -39,6 +39,9 @@ into
 .IR mine ,
 surrounding all conflicts with bracket lines.
 .TP
+.B \-B
+Old behavior of -A.  Shows non-conflicts.
+.TP
 .B \-e
 Generate an
 .I ed