This patch makes emission of /CreationDate and /ModDate headers optional.

If the environment variable GS_GENERATE_UUIDS is set to "0" or "no", it will
not write out the "/ID" field (if that's permissible).

Upstream does not want to do this.

See: https://bugs.ghostscript.com/show_bug.cgi?id=698208
diff --git a/devices/vector/gdevpdf.c b/devices/vector/gdevpdf.c
index cb268f62e..c5abefde2 100644
--- a/devices/vector/gdevpdf.c
+++ b/devices/vector/gdevpdf.c
@@ -425,6 +425,9 @@ pdf_initialize_ids(gx_device_pdf * pdev)
      * date and time, rather than (for example) %%CreationDate from the
      * PostScript file.  We think this is wrong, but we do the same.
      */
+    if (!getenv("GS_GENERATE_UUIDS") ||
+        (strcasecmp(getenv("GS_GENERATE_UUIDS"), "0") != 0 &&
+         strcasecmp(getenv("GS_GENERATE_UUIDS"), "no") != 0))
     {
         struct tm tms;
         time_t t;
diff --git a/devices/vector/gdevpdfe.c b/devices/vector/gdevpdfe.c
index ec011d8ba..f083f1e93 100644
--- a/devices/vector/gdevpdfe.c
+++ b/devices/vector/gdevpdfe.c
@@ -696,6 +696,9 @@ pdf_write_document_metadata(gx_device_pdf *pdev, const byte digest[6])
             pdf_xml_attribute_name(s, "xmlns:xmp");
             pdf_xml_attribute_value(s, "http://ns.adobe.com/xap/1.0/");
             pdf_xml_tag_end(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, "xmp:ModifyDate");
                 pdf_xml_tag_end(s);
@@ -704,6 +707,9 @@ pdf_write_document_metadata(gx_device_pdf *pdev, const byte digest[6])
                 pdf_xml_tag_close(s, "xmp:ModifyDate");
                 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, "xmp:CreateDate");
                 pdf_xml_tag_end(s);
c</a>/<a href='/guix/log/etc/snippets?id=f7f3d98e2d14382461360d1cae081dd916df7f06'>snippets</a>/<a href='/guix/log/etc/snippets/yas?id=f7f3d98e2d14382461360d1cae081dd916df7f06'>yas</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/etc/snippets/yas?id=f7f3d98e2d14382461360d1cae081dd916df7f06&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-02-19 21:13:23 -0500'>2023-02-19</span></td><td><a href='/guix/commit/etc/snippets/yas?id=633ead4afc78cfe65d9c8e629a4af4a80d969eb4'>etc: Add a news entry snippet.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/snippets/yas/scheme-mode/guix-news-entry: New file.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-11-28 23:34:15 +0100'>2022-11-28</span></td><td><a href='/guix/commit/etc/snippets/yas?id=fcb59fe24afc064b87b3abaf91140d015b4eb889'>snippets: yas: Add snippets for vc.el</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/snippets/yas/log-edit-mode/guix-vc-commit-message-add-package:
* etc/snippets/yas/log-edit-mode/guix-vc-commit-message-remove-package:
* etc/snippets/yas/log-edit-mode/guix-vc-commit-message-rename-package:
* etc/snippets/yas/log-edit-mode/guix-vc-commit-message-update-package:
* etc/snippets/yas/log-edit-mode/guix-vc-commit-message-use-https-home-page:
New file

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Morgan Smith</td></tr>
<tr><td><span title='2022-08-30 11:50:15 +0200'>2022-08-30</span></td><td><a href='/guix/commit/etc/snippets/yas?id=47c11772dfe840a536ed7ec438fe832878f51054'>etc: Update yasnippet build system list.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/snippets/yas/scheme-mode/guix-package (build-system): Add
chicken-build-system, minetest-build-system, rebar-build-system
and renpy-build-system.

Signed-off-by: Liliana Marie Prikler &lt;liliana.prikler@gmail.com&gt;
</span></span></td><td>Nicolas Graves</td></tr>
<tr><td><span title='2022-08-30 11:50:14 +0200'>2022-08-30</span></td><td><a href='/guix/commit/etc/snippets/yas?id=c4acaf412064568a546034871a9e0d3888aa7937'>etc: Add tempel snippets.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/snippets/tempel/scheme-mode: New file.
* etc/snippets/tempel/text-mode: New file.
* etc/snippets/scheme-mode: Moved from here...
* etc/snippets/yas/scheme-mode: ... to here.
* etc/snippets/text-mode: Moved from here...
* etc/snippets/yas/text-mode: ... to here.
* doc/contributing.texi ("The Perfect Setup"): Adjust yasnippet setup
accordingly.  Add tempel setup.

Signed-off-by: Liliana Marie Prikler &lt;liliana.prikler@gmail.com&gt;
</span></span></td><td>Nicolas Graves</td></tr>