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
@@ -617,7 +617,7 @@
         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));
@@ -719,15 +719,18 @@
             pdf_xml_tag_close(s, "rdf:Description");
             pdf_xml_newline(s);
 
-            pdf_xml_tag_open_beg(s, "rdf:Description");
-            pdf_xml_attribute_name(s, "rdf:about");
-            pdf_xml_attribute_value(s, instance_uuid);
-            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_attribute_name(s, "rdf:about");
+                pdf_xml_attribute_value(s, instance_uuid);
+                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_attribute_name(s, "rdf:about");
></td><td><a href='/guix/commit/NEWS?id=273cce9875a1deba2b6669099e69824db55c9622'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-11-23 15:42:01 +0100'>2018-11-23</span></td><td><a href='/guix/commit/NEWS?id=4bd5b9707e14bd5ad4da6868687ff3c642705ce3'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-08-30 15:22:30 +0200'>2018-08-30</span></td><td><a href='/guix/commit/NEWS?id=0f377aad75314df6c6296f4172801519315d81cd'>Update NEWS.</a></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2018-07-05 22:16:39 +0200'>2018-07-05</span></td><td><a href='/guix/commit/NEWS?id=359fdda40f754bbf1b5dc261e7427b75463b59be'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-07-05 17:19:09 +0200'>2018-07-05</span></td><td><a href='/guix/commit/NEWS?id=1400776f529317c6c3529a0fda2b728e48a621a2'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-06-20 23:47:08 +0200'>2018-06-20</span></td><td><a href='/guix/commit/NEWS?id=414ee4edc9e6fcadba366072a7ebabf3e3c6f26a'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-05-29 14:05:11 +0200'>2018-05-29</span></td><td><a href='/guix/commit/NEWS?id=55a433ebb0b2deb69141619d0a0b1e298a969c36'>Update NEWS.</a></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2018-05-20 21:42:32 +0300'>2018-05-20</span></td><td><a href='/guix/commit/NEWS?id=e9d271ed9a1fba86f372986a137b6110a41a1324'>services: Add Enlightenment desktop service.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2018-05-08 21:55:46 -0700'>2018-05-08</span></td><td><a href='/guix/commit/NEWS?id=ede121de426f9c56820852888a0b370f0ccbce49'>guix: Separate the package name and version with "@", not "-".</a><span class='msg-avail'>...</span></td><td>Chris Marusich</td></tr>
<tr><td><span title='2017-12-06 09:14:53 +0100'>2017-12-06</span></td><td><a href='/guix/commit/NEWS?id=40f5c53d89da266055a1dd6571c380f5c57fe5f9'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-12-06 08:58:26 +0100'>2017-12-06</span></td><td><a href='/guix/commit/NEWS?id=f0eb57b736f6fae67acbaad66a1b5e18fdfc10a0'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-12-05 15:37:01 +0100'>2017-12-05</span></td><td><a href='/guix/commit/NEWS?id=f3e3f4d934ee0ecd71f5c73a57252ed1d0bad88e'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-12-04 17:56:11 +0100'>2017-12-04</span></td><td><a href='/guix/commit/NEWS?id=c735e9e6868bb7661f08ffa008f1feaedf2fcb9e'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>