Merge pull request #7440 from Snuffleupagus/bug-874482

Prevent destinations with bad left/top values from scrolling the wrong page into view (bug 874482)

web/app.js

@@ -1187,7 +1187,7 @@ var PDFViewerApplication = {
 
     this.forceRendering();
 
-    this.pdfViewer.scrollPageIntoView(pageNumber);
+    this.pdfViewer.currentPageNumber = pageNumber;
   },
 
   requestPresentationMode: function pdfViewRequestPresentationMode() {

web/pdf_find_controller.js

@@ -308,7 +308,7 @@ var PDFFindController = (function PDFFindControllerClosure() {
         // If the page is selected, scroll the page into view, which triggers
         // rendering the page, which adds the textLayer. Once the textLayer is
         // build, it will scroll onto the selected match.
-        this.pdfViewer.scrollPageIntoView(index + 1);
+        this.pdfViewer.currentPageNumber = index + 1;
       }
 
       var page = this.pdfViewer.getPageView(index);

web/pdf_link_service.js

@@ -115,7 +115,10 @@ var PDFLinkService = (function PDFLinkServiceClosure() {
                           'Trying to navigate to a non-existent page.');
             return;
           }
-          self.pdfViewer.scrollPageIntoView(pageNumber, dest);
+          self.pdfViewer.scrollPageIntoView({
+            pageNumber: pageNumber,
+            destArray: dest,
+          });
 
           if (self.pdfHistory) {
             // Update the browsing history.
@@ -241,7 +244,11 @@ var PDFLinkService = (function PDFLinkServiceClosure() {
           }
         }
         if (dest) {
-          this.pdfViewer.scrollPageIntoView(pageNumber || this.page, dest);
+          this.pdfViewer.scrollPageIntoView({
+            pageNumber: pageNumber || this.page,
+            destArray: dest,
+            allowNegativeOffset: true,
+          });
         } else if (pageNumber) {
           this.page = pageNumber; // simple page
         }

web/pdf_viewer.js

@@ -458,7 +458,11 @@ var PDFViewer = (function pdfViewer() {
           dest = [null, { name: 'XYZ' }, this._location.left,
                   this._location.top, null];
         }
-        this.scrollPageIntoView(page, dest);
+        this.scrollPageIntoView({
+          pageNumber: page,
+          destArray: dest,
+          allowNegativeOffset: true,
+        });
       }
 
       this._setScaleDispatchEvent(newScale, newValue, preset);
@@ -531,16 +535,38 @@ var PDFViewer = (function pdfViewer() {
     },
 
     /**
-     * Scrolls page into view.
-     * @param {number} pageNumber
-     * @param {Array} dest - (optional) original PDF destination array:
-     *   <page-ref> </XYZ|FitXXX> <args..>
+     * @typedef ScrollPageIntoViewParameters
+     * @param {number} pageNumber - The page number.
+     * @param {Array} destArray - (optional) The original PDF destination array,
+     *   in the format: <page-ref> </XYZ|/FitXXX> <args..>
+     * @param {boolean} allowNegativeOffset - (optional) Allow negative page
+     *   offsets. The default value is `false`.
      */
-    scrollPageIntoView: function PDFViewer_scrollPageIntoView(pageNumber,
-                                                              dest) {
+
+    /**
+     * Scrolls page into view.
+     * @param {ScrollPageIntoViewParameters} params
+     */
+    scrollPageIntoView: function PDFViewer_scrollPageIntoView(params) {
       if (!this.pdfDocument) {
         return;
       }
+//#if GENERIC
+      if (arguments.length > 1 || typeof params === 'number') {
+        console.warn('Call of scrollPageIntoView() with obsolete signature.');
+        var paramObj = {};
+        if (typeof params === 'number') {
+          paramObj.pageNumber = params; // pageNumber argument was found.
+        }
+        if (arguments[1] instanceof Array) {
+          paramObj.destArray = arguments[1]; // destArray argument was found.
+        }
+        params = paramObj;
+      }
+//#endif
+      var pageNumber = params.pageNumber || 0;
+      var dest = params.destArray || null;
+      var allowNegativeOffset = params.allowNegativeOffset || false;
 
       if (this.isInPresentationMode || !dest) {
         this._setCurrentPageNumber(pageNumber, /* resetCurrentPageView */ true);
@@ -548,6 +574,11 @@ var PDFViewer = (function pdfViewer() {
       }
 
       var pageView = this._pages[pageNumber - 1];
+      if (!pageView) {
+        console.error('PDFViewer_scrollPageIntoView: ' +
+                      'Invalid "pageNumber" parameter.');
+        return;
+      }
       var x = 0, y = 0;
       var width = 0, height = 0, widthScale, heightScale;
       var changeOrientation = (pageView.rotation % 180 === 0 ? false : true);
@@ -628,6 +659,13 @@ var PDFViewer = (function pdfViewer() {
       var left = Math.min(boundingRect[0][0], boundingRect[1][0]);
       var top = Math.min(boundingRect[0][1], boundingRect[1][1]);
 
+      if (!allowNegativeOffset) {
+        // Some bad PDF generators will create destinations with e.g. top values
+        // that exceeds the page height. Ensure that offsets are not negative,
+        // to prevent a previous page from becoming visible (fixes bug 874482).
+        left = Math.max(left, 0);
+        top = Math.max(top, 0);
+      }
       scrollIntoView(pageView.div, { left: left, top: top });
     },