From 031428611c18bb4d97bbdbd11a7549ca2b96ccec Mon Sep 17 00:00:00 2001
From: Andras Simonyi <andras.simonyi@gmail.com>
Date: Sat, 11 May 2024 11:20:41 +0200
Subject: [PATCH] oc-csl: New custom option
 `org-cite-csl-sentence-case-bibtex-titles'

* lisp/oc-csl.el (org-cite-csl-sentence-case-bibtex-titles): New
variable.
(org-cite-csl--processor): Create the itemgetter using the new option.
* etc/ORG-NEWS (New option
~org-cite-csl-sentence-case-bibtex-titles~): Announce the change.
---
 etc/ORG-NEWS   |  9 +++++++++
 lisp/oc-csl.el | 18 +++++++++++++++++-
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index 36eeddda1..9ca71d0a2 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -1128,6 +1128,15 @@ blocks that do not specify any ~:formatter~ parameter. Its default
 value (the new function ~org-columns-dblock-write-default~) yields the
 previous (fixed) formatting behaviour.
 
+*** New option ~org-cite-csl-sentence-case-bibtex-titles~
+
+When this option is non-nil then title fields in bibtex bibliography
+entries are converted to sentence-case before being formatted
+according to a CSL style, except for entries with a =langid= field
+specifying a non-English language.  When nil, this conversion is
+limited to entries having a =langid= field specifying a variant of
+English.  The defult value is ~t~.
+
 ** New features
 *** =ob-lua=: Support all types and multiple values in results
 
diff --git a/lisp/oc-csl.el b/lisp/oc-csl.el
index 9bbe5e29d..7234174d0 100644
--- a/lisp/oc-csl.el
+++ b/lisp/oc-csl.el
@@ -321,6 +321,21 @@ in the bibliography measured in characters."
   :type 'string
   :package-version '(Org . "9.7"))
 
+(defcustom org-cite-csl-sentence-case-bibtex-titles t
+  "Convert bibtex title fields to sentence-case by default.
+
+When non-nil, title fields in bibtex bibliography entries are
+converted to sentence-case before being formatted according to a
+CSL style, except for entries with a `langid' field specifying a
+non-English language.
+
+When nil, this conversion is limited to entries having a `langid'
+field specifying a variant of English."
+  :group 'org-cite
+  :package-version '(Org . "9.7")
+  :type 'boolean
+  :safe #'booleanp)
+
 
 ;;; Internal variables
 (defconst org-cite-csl--etc-dir
@@ -584,7 +599,8 @@ property in INFO."
              (processor
               (citeproc-create
                (org-cite-csl--style-file info)
-               (citeproc-hash-itemgetter-from-any bibliography)
+               (citeproc-hash-itemgetter-from-any
+                bibliography (not org-cite-csl-sentence-case-bibtex-titles))
                (org-cite-csl--locale-getter)
                locale)))
         (plist-put info :cite-citeproc-processor processor)
-- 
2.34.1