bug#27563: [PATCH v3 2/2] gnu: ghostscript: Write document ID only when encrypting.

[Danny Milosavljevic <dannym@scratchpost.org>]

* gnu/packages/patches/ghostscript-no-header-id.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/ghostscript.scm (ghostscript)[source]: Use it.
---
 gnu/local.mk                                       |  1 +
 gnu/packages/ghostscript.scm                       |  1 +
 .../patches/ghostscript-no-header-id.patch         | 47 ++++++++++++++++++++++
 3 files changed, 49 insertions(+)
 create mode 100644 gnu/packages/patches/ghostscript-no-header-id.patch

diff --git a/gnu/local.mk b/gnu/local.mk
index 9eb6ac2d6..935794550 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -620,6 +620,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/ghc-dont-pass-linker-flags-via-response-files.patch	\
   %D%/packages/patches/ghostscript-CVE-2017-8291.patch		\
   %D%/packages/patches/ghostscript-runpath.patch		\
+  %D%/packages/patches/ghostscript-no-header-id.patch		\
   %D%/packages/patches/ghostscript-no-header-uuid.patch		\
   %D%/packages/patches/glib-networking-ssl-cert-file.patch	\
   %D%/packages/patches/glib-tests-timer.patch			\
diff --git a/gnu/packages/ghostscript.scm b/gnu/packages/ghostscript.scm
index 0b2787c68..f983fb20b 100644
--- a/gnu/packages/ghostscript.scm
+++ b/gnu/packages/ghostscript.scm
@@ -144,6 +144,7 @@ printing, and psresize, for adjusting page sizes.")
           "0lyhjcrkmd5fcmh8h56bs4xr9k4jasmikv5vsix1hd4ai0ad1q9b"))
         (patches (search-patches "ghostscript-runpath.patch"
                                  "ghostscript-CVE-2017-8291.patch"
+                                 "ghostscript-no-header-id.patch"
                                  "ghostscript-no-header-uuid.patch"))
         (modules '((guix build utils)))
         (snippet
diff --git a/gnu/packages/patches/ghostscript-no-header-id.patch b/gnu/packages/patches/ghostscript-no-header-id.patch
new file mode 100644
index 000000000..3526a300e
--- /dev/null
+++ b/gnu/packages/patches/ghostscript-no-header-id.patch
@@ -0,0 +1,47 @@
+--- ./devices/vector/gdevpdf.c.orig	2017-07-06 11:08:33.671196250 +0200
++++ ./devices/vector/gdevpdf.c	2017-07-06 11:39:25.282006143 +0200
+@@ -1759,8 +1759,11 @@
+      * +1 for the linearisation dict and +1 for the primary hint stream.
+      */
+     linear_params->FirsttrailerOffset = gp_ftell_64(linear_params->Lin_File.file);
+-    gs_sprintf(LDict, "\ntrailer\n<</Size %ld/Info %d 0 R/Root %d 0 R/ID[%s%s]/Prev %d>>\nstartxref\r\n0\n%%%%EOF\n        \n",
+-        linear_params->LastResource + 3, pdev->ResourceUsage[linear_params->Info_id].NewObjectNumber, pdev->ResourceUsage[linear_params->Catalog_id].NewObjectNumber, fileID, fileID, 0);
++    gs_sprintf(LDict, "\ntrailer\n<</Size %ld/Info %d 0 R/Root %d 0 R",
++        linear_params->LastResource + 3, pdev->ResourceUsage[linear_params->Info_id].NewObjectNumber, pdev->ResourceUsage[linear_params->Catalog_id].NewObjectNumber);
++    if (pdev->OwnerPassword.size > 0) /* ID is mandatory when encrypting */
++        gs_sprintf(LDict, "/ID[%s%s]", fileID, fileID);
++    gs_sprintf(LDict, "/Prev %d>>\nstartxref\r\n0\n%%%%EOF\n        \n", 0);
+     fwrite(LDict, strlen(LDict), 1, linear_params->Lin_File.file);
+ 
+     /* Write document catalog (Part 4) */
+@@ -2292,8 +2295,11 @@
+      * in the missing values.
+      */
+     code = gp_fseek_64(linear_params->sfile, linear_params->FirsttrailerOffset, SEEK_SET);
+-    gs_sprintf(LDict, "\ntrailer\n<</Size %ld/Info %d 0 R/Root %d 0 R/ID[%s%s]/Prev %"PRId64">>\nstartxref\r\n0\n%%%%EOF\n",
+-        linear_params->LastResource + 3, pdev->ResourceUsage[linear_params->Info_id].NewObjectNumber, pdev->ResourceUsage[linear_params->Catalog_id].NewObjectNumber, fileID, fileID, mainxref);
++    gs_sprintf(LDict, "\ntrailer\n<</Size %ld/Info %d 0 R/Root %d 0 R",
++        linear_params->LastResource + 3, pdev->ResourceUsage[linear_params->Info_id].NewObjectNumber, pdev->ResourceUsage[linear_params->Catalog_id].NewObjectNumber);
++    if (pdev->OwnerPassword.size > 0) /* ID is mandatory when encrypting */
++        gs_sprintf(LDict, "/ID[%s%s]", fileID, fileID);
++    gs_sprintf(LDict, "/Prev %"PRId64">>\nstartxref\r\n0\n%%%%EOF\n", mainxref);
+     fwrite(LDict, strlen(LDict), 1, linear_params->sfile);
+ 
+     code = gp_fseek_64(linear_params->sfile, pdev->ResourceUsage[HintStreamObj].LinearisedOffset, SEEK_SET);
+@@ -2930,10 +2936,12 @@
+             stream_puts(s, "trailer\n");
+             pprintld3(s, "<< /Size %ld /Root %ld 0 R /Info %ld 0 R\n",
+                   pdev->next_id, Catalog_id, Info_id);
+-            stream_puts(s, "/ID [");
+-            psdf_write_string(pdev->strm, pdev->fileID, sizeof(pdev->fileID), 0);
+-            psdf_write_string(pdev->strm, pdev->fileID, sizeof(pdev->fileID), 0);
+-            stream_puts(s, "]\n");
++            if (pdev->OwnerPassword.size > 0) { /* ID is mandatory when encrypting */
++                stream_puts(s, "/ID [");
++                psdf_write_string(pdev->strm, pdev->fileID, sizeof(pdev->fileID), 0);
++                psdf_write_string(pdev->strm, pdev->fileID, sizeof(pdev->fileID), 0);
++                stream_puts(s, "]\n");
++            }
+             if (pdev->OwnerPassword.size > 0) {
+                 pprintld1(s, "/Encrypt %ld 0 R ", Encrypt_id);
+             }