app-text/paperwork-backend: fix PDF file segfault

Backport from upstream workaround

Closes: https://bugs.gentoo.org/765526
Signed-off-by: Bernard Cafarelli <voyageur@gentoo.org>

2 files changed, 115 insertions, 0 deletions

diff --git a/app-text/paperwork-backend/files/paperwork-backend-2.2.1-cairo_workaround.patch b/app-text/paperwork-backend/files/paperwork-backend-2.2.1-cairo_workaround.patch
new file mode 100644
index 000000000000..01eb2a6154b0
--- /dev/null
+++ b/app-text/paperwork-backend/files/paperwork-backend-2.2.1-cairo_workaround.patch
@@ -0,0 +1,52 @@
+From c9430b844fbcedc9119e3d464f5f0c85feb7b197 Mon Sep 17 00:00:00 2001
+From: Jerome Flesch <jflesch@openpaper.work>
+Date: Sun, 4 Feb 2024 20:33:27 +0100
+Subject: [PATCH] Backend/docexport PDF: Workaround Cairo bug that causes
+ occasional crashes when exporting to generated PDF.
+
+Closes #942
+---
+ .../src/paperwork_backend/docexport/pdf.py          | 13 +++++++++++++
+ 1 file changed, 13 insertions(+)
+
+diff --git a/paperwork-backend/src/paperwork_backend/docexport/pdf.py b/paperwork-backend/src/paperwork_backend/docexport/pdf.py
+index 160e60710..befded73c 100644
+--- a/paperwork-backend/src/paperwork_backend/docexport/pdf.py
++++ b/paperwork-backend/src/paperwork_backend/docexport/pdf.py
+@@ -115,6 +115,8 @@ class PdfCreator(object):
+         )
+         self.pdf_context = cairo.Context(self.pdf_surface)
+ 
++        self.gc_protection = []  # WORKAROUND(Jflesch): Cairo crash
++
+     def set_page_size(self, img_size):
+         # portrait or landscape
+         if (img_size[0] < img_size[1]):
+@@ -187,6 +189,16 @@ class PdfCreator(object):
+             "pillow_to_surface", img,
+             intermediate="jpeg", quality=int(self.quality * 100)
+         )
++        # WORKAROUND(Jflesch):
++        # If Cairo supports JPEG embedding, we use
++        # cairo.ImageSurface.set_mime_data() instead of the usual Cairo
++        # surface functions to draw the image. It seems this function does
++        # not increment the ref counter of the surface object
++        # --> the Python GC tends to collect it while Cairo is still going
++        # to use it to generate the PDF.
++        # --> we have to keep a reference on it ourselves, until the page has
++        # been generated.
++        self.gc_protection.append(img_surface)
+ 
+         self.pdf_context.save()
+         try:
+@@ -199,6 +211,7 @@ class PdfCreator(object):
+ 
+     def next_page(self):
+         self.pdf_context.show_page()
++        self.gc_protection = []  # WORKAROUND(Jflesch): Cairo crash
+ 
+     def finish(self):
+         self.pdf_surface.flush()
+-- 
+GitLab
+
diff --git a/app-text/paperwork-backend/paperwork-backend-2.2.1-r1.ebuild b/app-text/paperwork-backend/paperwork-backend-2.2.1-r1.ebuild
new file mode 100644
index 000000000000..bb7a9c75061b
--- /dev/null
+++ b/app-text/paperwork-backend/paperwork-backend-2.2.1-r1.ebuild
@@ -0,0 +1,63 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+DISTUTILS_USE_PEP517=setuptools
+PYTHON_COMPAT=( python3_{9..12} )
+
+inherit distutils-r1
+
+DESCRIPTION="Backend part of Paperwork (Python API, no UI)"
+HOMEPAGE="https://gitlab.gnome.org/World/OpenPaperwork"
+# Update from release hash at:
+# https://gitlab.gnome.org/World/OpenPaperwork/paperwork/-/tags
+REL_HASH="0bea4054"
+SRC_URI="https://gitlab.gnome.org/World/OpenPaperwork/paperwork/-/archive/${PV}/paperwork-${PV}.tar.bz2
+	https://download.openpaper.work/data/paperwork/master_${REL_HASH}/data.tar.gz -> paperwork-data-${PV}.tar.gz"
+
+LICENSE="GPL-3"
+SLOT="0"
+KEYWORDS="~amd64 ~x86"
+
+RDEPEND="
+	app-text/openpaperwork-core[${PYTHON_USEDEP}]
+	app-text/openpaperwork-gtk[${PYTHON_USEDEP}]
+	app-text/poppler[introspection]
+	dev-python/distro[${PYTHON_USEDEP}]
+	dev-python/pillow[${PYTHON_USEDEP}]
+	dev-python/psutil[${PYTHON_USEDEP}]
+	dev-python/pycairo[${PYTHON_USEDEP}]
+	dev-python/pycountry[${PYTHON_USEDEP}]
+	dev-python/pygobject:3[${PYTHON_USEDEP}]
+	dev-python/termcolor[${PYTHON_USEDEP}]
+	dev-python/whoosh[${PYTHON_USEDEP}]
+	sci-libs/scikit-learn[${PYTHON_USEDEP}]
+"
+BDEPEND="
+	${RDEPEND}
+	dev-python/setuptools-scm[${PYTHON_USEDEP}]
+	sys-apps/which
+	sys-devel/gettext
+	test? (
+		dev-python/libpillowfight[${PYTHON_USEDEP}]
+		media-libs/libinsane
+	)
+"
+S=${WORKDIR}/paperwork-${PV}/${PN}
+
+distutils_enable_tests unittest
+
+export SETUPTOOLS_SCM_PRETEND_VERSION=${PV}
+
+src_prepare() {
+	default
+	cd "${WORKDIR}"/paperwork-${PV} || die
+	eapply "${FILESDIR}"/${P}-cairo_workaround.patch
+}
+
+python_compile() {
+	emake l10n_compile
+
+	distutils-r1_python_compile
+}