texlive[68136] Build/source/texk/web2c/pdftexdir: (cmp_return): doc

[commits+karl at tug.org]

Revision: 68136
          http://tug.org/svn/texlive?view=revision&revision=68136
Author:   karl
Date:     2023-09-01 16:59:58 +0200 (Fri, 01 Sep 2023)
Log Message:
-----------
(cmp_return): doc

Modified Paths:
--------------
    trunk/Build/source/texk/web2c/pdftexdir/ChangeLog
    trunk/Build/source/texk/web2c/pdftexdir/ptexmac.h

Modified: trunk/Build/source/texk/web2c/pdftexdir/ChangeLog
===================================================================
--- trunk/Build/source/texk/web2c/pdftexdir/ChangeLog	2023-09-01 14:47:24 UTC (rev 68135)
+++ trunk/Build/source/texk/web2c/pdftexdir/ChangeLog	2023-09-01 14:59:58 UTC (rev 68136)
@@ -1,3 +1,9 @@
+2023-09-01  Karl Berry  <karl at freefriends.org>
+
+	* ptexmac.h (cmp_return): a few words of documentation about
+	the seemingly strange lack of handling the a==b case.
+	Suggested by Jim Diamond.
+
 2023-08-28  Karl Berry  <karl at freefriends.org>
 
 	* tounicode.c (undump_to_unicode): check that gu->name

Modified: trunk/Build/source/texk/web2c/pdftexdir/ptexmac.h
===================================================================
--- trunk/Build/source/texk/web2c/pdftexdir/ptexmac.h	2023-09-01 14:47:24 UTC (rev 68135)
+++ trunk/Build/source/texk/web2c/pdftexdir/ptexmac.h	2023-09-01 14:59:58 UTC (rev 68136)
@@ -207,6 +207,10 @@
     cur_file_name = s;      \
     packfilename(maketexstring(cur_file_name), getnullstr(), getnullstr())
 
+/* This macro doesn't handle the case where a==b. It turns out that is
+ * convenient for the way it's used; for example, see writettf.c.
+ * All uses (must) follow the same pattern.
+ */
 #  define cmp_return(a, b) \
     if ((a) > (b))         \
         return 1;        \