This patch makes the UUIDs in the XMP header optional, depending on the
setting of the environment variable GS_GENERATE_UUIDS.

If the environment variable GS_GENERATE_UUIDS is set to "0" or "no", it will
not write out the Document UUID field and also will write the Instance ID
field value as "".

Upstream does not want to do this.

See: https://bugs.ghostscript.com/show_bug.cgi?id=698208
diff -ur orig/gnu-ghostscript-9.14.0/devices/vector/gdevpdfe.c aa/gnu-ghostscript-9.14.0/devices/vector/gdevpdfe.c
--- orig/gnu-ghostscript-9.14.0/devices/vector/gdevpdfe.c	2017-07-09 23:30:28.960479189 +0200
+++ gnu-ghostscript-9.14.0/devices/vector/gdevpdfe.c	2017-07-10 01:04:12.252478276 +0200
@@ -620,7 +620,7 @@
         return code;
 
     /* PDF/A XMP reference recommends setting UUID to empty. If not empty must be a URI */
-    if (pdev->PDFA != 0)
+    if (pdev->PDFA != 0 || (getenv("GS_GENERATE_UUIDS") && (strcasecmp(getenv("GS_GENERATE_UUIDS"), "0") == 0 || strcasecmp(getenv("GS_GENERATE_UUIDS"), "no") == 0)))
         instance_uuid[0] = 0x00;
 
     cre_date_time_len = pdf_get_docinfo_item(pdev, "/CreationDate", cre_date_time, sizeof(cre_date_time));
@@ -720,14 +720,17 @@
             pdf_xml_tag_close(s, "rdf:Description");
             pdf_xml_newline(s);
 
-            pdf_xml_tag_open_beg(s, "rdf:Description");
-            pdf_xml_copy(s, " rdf:about=\"\"");
-            pdf_xml_attribute_name(s, "xmlns:xapMM");
-            pdf_xml_attribute_value(s, "http://ns.adobe.com/xap/1.0/mm/");
-            pdf_xml_attribute_name(s, "xapMM:DocumentID");
-            pdf_xml_attribute_value(s, document_uuid);
-            pdf_xml_tag_end_empty(s);
-            pdf_xml_newline(s);
+            if (!getenv("GS_GENERATE_UUIDS") || (strcasecmp(getenv("GS_GENERATE_UUIDS"), "0") != 0 && strcasecmp(getenv("GS_GENERATE_UUIDS"), "no") != 0))
+            {
+                pdf_xml_tag_open_beg(s, "rdf:Description");
+                pdf_xml_copy(s, " rdf:about=\"\"");
+                pdf_xml_attribute_name(s, "xmlns:xapMM");
+                pdf_xml_attribute_value(s, "http://ns.adobe.com/xap/1.0/mm/");
+                pdf_xml_attribute_name(s, "xapMM:DocumentID");
+                pdf_xml_attribute_value(s, document_uuid);
+                pdf_xml_tag_end_empty(s);
+                pdf_xml_newline(s);
+            }
 
             pdf_xml_tag_open_beg(s, "rdf:Description");
             pdf_xml_copy(s, " rdf:about=\"\"");
st nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/bournish.scm?id=2bc967e53dc6fd31f333485e614040581cd0052c'>Collapse</a>)</th><th class='left'>Author</th></tr>
31:59 +0300'>2020-08-19</span></td><td><a href='/guix/commit/gnu/packages/fvwm.scm?id=c0153167e83947641f806d7f8d9f21eeba5c5803'>gnu: fvwm: Use make-desktop-entry-file.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/fvwm.scm (fvwm)[arguments]: Adjust 'install-xsession to
  use make-desktop-entry-file.
</span></span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2020-08-19 16:14:57 +0300'>2020-08-19</span></td><td><a href='/guix/commit/gnu/packages/fvwm.scm?id=678fdbb37a6fa5a24413f5550c29f446945e6e23'>gnu: fvwm: Use https.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/fvwm.scm (fvwm)[home-page]: Use https.
</span></span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2020-05-13 09:30:26 +0300'>2020-05-13</span></td><td><a href='/guix/commit/gnu/packages/fvwm.scm?id=3c986a7dc268756c097212de958f046b29b76c1b'>mailmap: Update entries for Nikita.</a><span class='msg-avail'>...<span class='msg-tooltip'>* .mailmap: change email and name for Nikita.
* Makefile.am, doc/guix.texi, etc/completion/fish/guix.fish,
gnu/packages/accessibility.scm, gnu/packages/admin.scm,
gnu/packages/audio.scm, gnu/packages/autotools.scm, gnu/packages/cdrom.scm,
gnu/packages/check.scm, gnu/packages/cinnamon.scm,
gnu/packages/compression.scm, gnu/packages/crypto.scm,
gnu/packages/databases.scm, gnu/packages/django.scm, gnu/packages/dns.scm,
gnu/packages/elixir.scm, gnu/packages/emacs-xyz.scm, gnu/packages/emacs.scm,
gnu/packages/enlightenment.scm, gnu/packages/erlang.scm,
gnu/packages/fonts.scm, gnu/packages/fontutils.scm, gnu/packages/forth.scm,
gnu/packages/fvwm.scm, gnu/packages/games.scm, gnu/packages/gl.scm,
gnu/packages/gnome.scm, gnu/packages/gnunet.scm, gnu/packages/gnupg.scm,
gnu/packages/gtk.scm, gnu/packages/guile-wm.scm, gnu/packages/guile-xyz.scm,
gnu/packages/haskell-apps.scm, gnu/packages/haskell-check.scm,
gnu/packages/haskell-crypto.scm, gnu/packages/haskell-xyz.scm,
gnu/packages/haskell.scm, gnu/packages/image-viewers.scm,
gnu/packages/image.scm, gnu/packages/irc.scm, gnu/packages/language.scm,
gnu/packages/libcanberra.scm, gnu/packages/linux.scm,
gnu/packages/lisp-xyz.scm, gnu/packages/lisp.scm, gnu/packages/lolcode.scm,
gnu/packages/lxde.scm, gnu/packages/lxqt.scm, gnu/packages/mail.scm,
gnu/packages/markup.scm, gnu/packages/mate.scm, gnu/packages/maths.scm,
gnu/packages/mc.scm, gnu/packages/messaging.scm, gnu/packages/music.scm,
gnu/packages/ncurses.scm, gnu/packages/networking.scm,
gnu/packages/nickle.scm, gnu/packages/openbox.scm, gnu/packages/pdf.scm,
gnu/packages/perl-check.scm, gnu/packages/perl.scm,
gnu/packages/python-compression.scm, gnu/packages/python-crypto.scm,
gnu/packages/python-web.scm, gnu/packages/python-xyz.scm,
gnu/packages/python.scm, gnu/packages/qt.scm, gnu/packages/ruby.scm,
gnu/packages/rust.scm, gnu/packages/scheme.scm,
gnu/packages/serialization.scm, gnu/packages/shells.scm,
gnu/packages/ssh.scm, gnu/packages/suckless.scm, gnu/packages/tbb.scm,
gnu/packages/telephony.scm, gnu/packages/text-editors.scm,
gnu/packages/textutils.scm, gnu/packages/time.scm, gnu/packages/tls.scm,
gnu/packages/tor.scm, gnu/packages/version-control.scm,
gnu/packages/video.scm, gnu/packages/vim.scm, gnu/packages/web.scm,
gnu/packages/wm.scm, gnu/packages/xdisorg.scm, gnu/packages/xfce.scm,
gnu/packages/xml.scm, gnu/packages/xorg.scm, gnu/services/certbot.scm,
gnu/services/desktop.scm, gnu/services/version-control.scm,
gnu/services/web.scm, guix/import/hackage.scm, guix/licenses.scm: Likewise.

Signed-off-by: Efraim Flashner &lt;efraim@flashner.co.il&gt;
</span></span></td><td>nikita</td></tr>