From 9a6b786c8372027ae48384bf4c62f358abf2a7e0 Mon Sep 17 00:00:00 2001
From: Pratik Dulal <pratikdulal0@gmail.com>
Date: Wed, 29 Jul 2026 16:05:49 +0545
Subject: [PATCH] fix: stop bare addPage() from re-forcing the document's
 default font

PDFPage's constructor applies options.font/options.fontSize whenever
they're set, but addPage() reuses the exact same options object passed
to the PDFDocument constructor when called with no arguments. So if a
default font was set via `new PDFDocument({ font: ... })`, every
subsequent bare addPage() call silently re-applied it, clobbering any
doc.font()/doc.fontSize() call made since the previous page (#1739).

initFonts() already applies the constructor's default font/fontSize
once, before the first page is even created, so PDFPage re-deriving
them from options was only ever necessary for two cases: the very
first page (harmless no-op re-application) and an explicit
addPage({ font, fontSize }) call, which is a documented way to
override for a specific page. Only apply them in those two cases now,
identified by checking whether the options object is the exact one
reused from document.options and whether a page already exists.
---
 lib/page.js             | 17 +++++++++++++++--
 tests/unit/page.spec.js | 30 ++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/lib/page.js b/lib/page.js
index 9a8b0be39..87d93db98 100644
--- a/lib/page.js
+++ b/lib/page.js
@@ -85,8 +85,21 @@ class PDFPage {
 
     this.content = this.document.ref();
 
-    if (options.font) document.font(options.font, options.fontFamily);
-    if (options.fontSize) document.fontSize(options.fontSize);
+    // `options` defaults to `document.options` (the PDFDocument constructor options) when
+    // addPage() is called without arguments, so it's the same object for every page. Applying
+    // font/fontSize from it unconditionally would silently override any doc.font()/doc.fontSize()
+    // call made since the previous page. Only (re-)apply them here when they were explicitly
+    // passed to this addPage() call, or for the very first page (document.page is still null),
+    // where they're the intended initial default - already applied by initFonts(), so this is
+    // just keeping fontSize/margin calculation below consistent.
+    const isInheritedDefaultOptions = options === document.options;
+    const isFirstPage = document.page == null;
+    if (options.font && (!isInheritedDefaultOptions || isFirstPage)) {
+      document.font(options.font, options.fontFamily);
+    }
+    if (options.fontSize && (!isInheritedDefaultOptions || isFirstPage)) {
+      document.fontSize(options.fontSize);
+    }
 
     // process margins
     // Margin calculation must occur after font assignment to ensure any dynamic sizes are calculated correctly
diff --git a/tests/unit/page.spec.js b/tests/unit/page.spec.js
index 8164517f4..1aff920e4 100644
--- a/tests/unit/page.spec.js
+++ b/tests/unit/page.spec.js
@@ -28,4 +28,34 @@ describe('page', function () {
       expect(page.margins).toEqual({ top: 0, right: 0, bottom: 0, left: 0 });
     });
   });
+
+  // https://github.com/foliojs/pdfkit/issues/1739
+  describe('font persistence across addPage()', function () {
+    test('a font set with doc.font() persists onto a bare addPage() call', function () {
+      const doc = new PDFDocument({ font: 'Helvetica' });
+      doc.font('Helvetica-Bold');
+      doc.addPage();
+      expect(doc._font.name).toBe('Helvetica-Bold');
+    });
+
+    test('a font size set with doc.fontSize() persists onto a bare addPage() call', function () {
+      const doc = new PDFDocument({ font: 'Helvetica' });
+      doc.fontSize(30);
+      doc.addPage();
+      expect(doc._fontSize).toBe(30);
+    });
+
+    test('an explicit font passed to addPage() still overrides the current font', function () {
+      const doc = new PDFDocument({ font: 'Helvetica' });
+      doc.font('Helvetica-Bold');
+      doc.addPage({ font: 'Times-Roman' });
+      expect(doc._font.name).toBe('Times-Roman');
+    });
+
+    test('an explicit fontSize passed to addPage() still applies', function () {
+      const doc = new PDFDocument({ font: 'Helvetica' });
+      doc.addPage({ fontSize: 20 });
+      expect(doc._fontSize).toBe(20);
+    });
+  });
 });