Fix automatic zoom under spread mode

web/base_viewer.js

@@ -725,6 +725,20 @@ class BaseViewer {
  }
  }
 
+ /**
+ * @private
+ */
+ get _pageWidthScaleFactor() {
+ if (
+ this.spreadMode !== SpreadMode.NONE &&
+ this.scrollMode !== ScrollMode.HORIZONTAL &&
+ !this.isInPresentationMode
+ ) {
+ return 2;
+ }
+ return 1;
+ }
+
  _setScale(value, noScroll = false) {
  let scale = parseFloat(value);
 
@@ -743,8 +757,9 @@ class BaseViewer {
  [hPadding, vPadding] = [vPadding, hPadding]; // Swap the padding values.
  }
  const pageWidthScale =
- ((this.container.clientWidth - hPadding) / currentPage.width) *
- currentPage.scale;
+ (((this.container.clientWidth - hPadding) / currentPage.width) *
+ currentPage.scale) /
+ this._pageWidthScaleFactor;
  const pageHeightScale =
  ((this.container.clientHeight - vPadding) / currentPage.height) *
  currentPage.scale;
@@ -1473,6 +1488,9 @@ class BaseViewer {
  if (!pageNumber) {
  return;
  }
+ if (this._currentScaleValue && isNaN(this._currentScaleValue)) {
+ this._setScale(this._currentScaleValue, true);
+ }
  this._setCurrentPageNumber(pageNumber, /* resetCurrentPageView = */ true);
  this.update();
  }

web/pdf_single_page_viewer.js

@@ -35,6 +35,10 @@ class PDFSinglePageViewer extends BaseViewer {
  return shadow(this, "_viewerElement", this._shadowViewer);
  }
 
+ get _pageWidthScaleFactor() {
+ return 1;
+ }
+
  _resetView() {
  super._resetView();
  this._previousPageNumber = 1;