fix: get accurate pdf page size (#1980)

Handles edge cases with PDF media boxes and crop boxes, deals with
certain documents that had been uploaded with weird combos of sizings.

packages/lib/server-only/pdf/add-rejection-stamp-to-pdf.ts

@@ -3,6 +3,7 @@ import type { PDFDocument } from 'pdf-lib';
 import { TextAlignment, rgb, setFontAndSize } from 'pdf-lib';
 
 import { NEXT_PUBLIC_WEBAPP_URL } from '../../constants/app';
+import { getPageSize } from './get-page-size';
 
 /**
  * Adds a rejection stamp to each page of a PDF document.
@@ -27,7 +28,7 @@ export async function addRejectionStampToPdf(
 
   for (let i = 0; i < pages.length; i++) {
     const page = pages[i];
-    const { width, height } = page.getSize();
+    const { width, height } = getPageSize(page);
 
     // Draw the "REJECTED" text
     const rejectedTitleText = 'DOCUMENT REJECTED';

packages/lib/server-only/pdf/get-page-size.ts

@@ -0,0 +1,18 @@
+import type { PDFPage } from 'pdf-lib';
+
+/**
+ * Gets the effective page size for PDF operations.
+ *
+ * Uses CropBox by default to handle rare cases where MediaBox is larger than CropBox.
+ * Falls back to MediaBox when it's smaller than CropBox, following typical PDF reader behavior.
+ */
+export const getPageSize = (page: PDFPage) => {
+  const cropBox = page.getCropBox();
+  const mediaBox = page.getMediaBox();
+
+  if (mediaBox.width < cropBox.width || mediaBox.height < cropBox.height) {
+    return mediaBox;
+  }
+
+  return cropBox;
+};

packages/lib/server-only/pdf/insert-field-in-pdf.ts

@@ -33,6 +33,7 @@ import {
   ZRadioFieldMeta,
   ZTextFieldMeta,
 } from '../../types/field-meta';
+import { getPageSize } from './get-page-size';
 
 export const insertFieldInPDF = async (pdf: PDFDocument, field: FieldWithSignature) => {
   const [fontCaveat, fontNoto] = await Promise.all([
@@ -77,7 +78,7 @@ export const insertFieldInPDF = async (pdf: PDFDocument, field: FieldWithSignatu
 
   const isPageRotatedToLandscape = pageRotationInDegrees === 90 || pageRotationInDegrees === 270;
 
-  let { width: pageWidth, height: pageHeight } = page.getSize();
+  let { width: pageWidth, height: pageHeight } = getPageSize(page);
 
   // PDFs can have pages that are rotated, which are correctly rendered in the frontend.
   // However when we load the PDF in the backend, the rotation is applied.

packages/lib/server-only/pdf/legacy-insert-field-in-pdf.ts

@@ -26,6 +26,7 @@ import {
   ZRadioFieldMeta,
   ZTextFieldMeta,
 } from '../../types/field-meta';
+import { getPageSize } from './get-page-size';
 
 export const legacy_insertFieldInPDF = async (pdf: PDFDocument, field: FieldWithSignature) => {
   const [fontCaveat, fontNoto] = await Promise.all([
@@ -63,7 +64,7 @@ export const legacy_insertFieldInPDF = async (pdf: PDFDocument, field: FieldWith
 
   const isPageRotatedToLandscape = pageRotationInDegrees === 90 || pageRotationInDegrees === 270;
 
-  let { width: pageWidth, height: pageHeight } = page.getSize();
+  let { width: pageWidth, height: pageHeight } = getPageSize(page);
 
   // PDFs can have pages that are rotated, which are correctly rendered in the frontend.
   // However when we load the PDF in the backend, the rotation is applied.