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);
='/guix/log/gnu?id=299455fef23fe878edfdede7bde254df067e623a'>gnu</a>/<a href='/guix/log/gnu/packages?id=299455fef23fe878edfdede7bde254df067e623a'>packages</a>/<a href='/guix/log/gnu/packages/openldap.scm?id=299455fef23fe878edfdede7bde254df067e623a'>openldap.scm</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/gnu/packages/openldap.scm?id=299455fef23fe878edfdede7bde254df067e623a&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
n class='msg-avail'>...<span class='msg-tooltip'>* guix/scripts/system.scm (show-help, %docker-format-options, %options,
%default-options, show-docker-format-options,
show-docker-format-options/detailed, process-action): Handle '--max-layers'
option.
* gnu/system/image.scm (system-docker-image): Same.
* gnu/image.scm (&lt;image&gt;)[max-layers]: New record field.

Change-Id: I2726655aefd6688b976057fd5a38e9972ebfc292
</span></span></td><td>Oleg Pykhalov</td></tr>