Subject: [bug#76922] [PATCH v2] gnu: cairo: Add patch to fix regression when writing PDFs with fonts

From: Remco van 't Veer <[email-masked]>
Date: Mon, 10 Mar 2025 21:29:17 +0100

Applied patch fixes out of memory errors when writing PDFs with fonts
in xournalpp and others.  See also:

  https://gitlab.freedesktop.org/cairo/cairo/-/issues/870

* gnu/local.mk: Register patch.
* gnu/packages/gtk.scm (cairo): Add patch.
* gnu/packages/patches/cairo-cff-dont-fail-if-no-local-subs: Add patch.
---
 gnu/local.mk                                  |  3 +-
 gnu/packages/gtk.scm                          |  9 +++++
 ...cairo-cff-dont-fail-if-no-local-subs.patch | 34 +++++++++++++++++++
 3 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 gnu/packages/patches/cairo-cff-dont-fail-if-no-local-subs.patch

diff --git a/gnu/local.mk b/gnu/local.mk
index 880af09168..f26c79b3e1 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -48,7 +48,7 @@
 # Copyright © 2021 Andrew Tropin <[email-masked]>
 # Copyright © 2021 Simon Tournier <[email-masked]>
 # Copyright © 2022 Daniel Meißner <[email-masked]>
-# Copyright © 2022, 2024 Remco van 't Veer <[email-masked]>
+# Copyright © 2022, 2024, 2025 Remco van 't Veer <[email-masked]>
 # Copyright © 2022, 2024 Artyom V. Poptsov <[email-masked]>
 # Copyright © 2022, 2023 John Kehayias <[email-masked]>
 # Copyright © 2022 muradm <[email-masked]>
@@ -1069,6 +1069,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/busybox-add-missing-sha-NI-guard.patch	\
   %D%/packages/patches/c2rust-ast-exporter-local-search.patch	\
   %D%/packages/patches/cadical-add-shared-library.patch		\
+  %D%/packages/patches/cairo-cff-dont-fail-if-no-local-subs.patch		\
   %D%/packages/patches/calibre-no-updates-dialog.patch		\
   %D%/packages/patches/calibre-remove-test-sqlite.patch		\
   %D%/packages/patches/calibre-remove-test-unrar.patch		\
diff --git a/gnu/packages/gtk.scm b/gnu/packages/gtk.scm
index 846103ff9e..09b1566e95 100644
--- a/gnu/packages/gtk.scm
+++ b/gnu/packages/gtk.scm
@@ -38,6 +38,7 @@
 ;;; Copyright © 2023 Janneke Nieuwenhuizen <[email-masked]>
 ;;; Copyright © 2024 John Kehayias <[email-masked]>
 ;;; Copyright © 2025 Florian Pelz <[email-masked]>
+;;; Copyright © 2025 Remco van 't Veer <[email-masked]>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -172,6 +173,7 @@ (define cairo
   (package
     (name "cairo")
     (version "1.18.2")
+    (replacement cairo-fixed)
     (source
      (origin
        (method url-fetch)
@@ -238,6 +240,13 @@ (define cairo
     ;; Hide and have cairo-with-documentation public.
     (properties '((hidden? . #t)))))
 
+(define cairo-fixed
+  (package
+    (inherit cairo)
+    (source (origin
+              (inherit (package-source cairo))
+              (patches (search-patches "cairo-cff-dont-fail-if-no-local-subs.patch"))))))
+
 (define-public cairo-with-documentation
   ;; cairo's docs must be built in a separate package since it requires
   ;; gtk-doc, which in turn depends on cairo.
diff --git a/gnu/packages/patches/cairo-cff-dont-fail-if-no-local-subs.patch b/gnu/packages/patches/cairo-cff-dont-fail-if-no-local-subs.patch
new file mode 100644
index 0000000000..ed1056a0c8
--- /dev/null
+++ b/gnu/packages/patches/cairo-cff-dont-fail-if-no-local-subs.patch
@@ -0,0 +1,34 @@
+From f19e2fe080ddcfce93c8234a919fd882f3d63362 Mon Sep 17 00:00:00 2001
+From: Adrian Johnson <[email-masked]>
+Date: Fri, 13 Sep 2024 06:28:39 +0930
+Subject: [PATCH] cff: Don't fail if no local subs
+
+Fixes: #870
+---
+ src/cairo-cff-subset.c | 10 +++++++---
+ 1 file changed, 7 insertions(+), 3 deletions(-)
+
+diff --git a/src/cairo-cff-subset.c b/src/cairo-cff-subset.c
+index 076cb2b0a..8a7de0065 100644
+--- a/src/cairo-cff-subset.c
++++ b/src/cairo-cff-subset.c
+@@ -952,9 +952,13 @@ cairo_cff_font_read_private_dict (cairo_cff_font_t   *font,
+ 	 decode_number (operand, nominal_width);
+ 
+     num_subs = _cairo_array_num_elements (local_sub_index);
+-    *local_subs_used = _cairo_calloc_ab (num_subs, sizeof (cairo_bool_t));
+-    if (unlikely (*local_subs_used == NULL))
+-	return _cairo_error (CAIRO_STATUS_NO_MEMORY);
++    if (num_subs > 0) {
++	*local_subs_used = _cairo_calloc_ab (num_subs, sizeof (cairo_bool_t));
++	if (unlikely (*local_subs_used == NULL))
++	    return _cairo_error (CAIRO_STATUS_NO_MEMORY);
++    } else {
++	*local_subs_used = NULL;
++    }
+ 
+     if (num_subs < 1240)
+ 	*local_sub_bias = 107;
+-- 
+GitLab
+

base-commit: d0510dcd824e1b3fda62a8841e792581d7b8de8d
-- 
2.48.1