PDF: Fix missing character when selecting backwards

pdf/pdfium/pdfium_engine.cc

Index: pdf/pdfium/pdfium_engine.cc
diff --git a/pdf/pdfium/pdfium_engine.cc b/pdf/pdfium/pdfium_engine.cc
index 87f8d65dc90e3a09695495146564febe52b6ce6c..3b98ced26f5cb0292e65c9ff81b39f94c62accf8 100644
--- a/pdf/pdfium/pdfium_engine.cc
+++ b/pdf/pdfium/pdfium_engine.cc
@@ -1863,7 +1863,9 @@ bool PDFiumEngine::OnMouseMove(const pp::MouseInputEvent& event) {
     selection_.push_back(PDFiumRange(pages_[page_index], 0, char_index));
   } else {
     // Selecting into the previous page.
-    selection_[last].SetCharCount(-selection_[last].char_index());
+    // As char_index starts from 0 so char count should be set one more than

[Lei Zhang, 2015/01/16 07:01:23]

I would write this as:

The selection's char_index is 0-based, so the character count is one more than
the index. The character count needs to be negative to indicate a backwards
selection.

[Deepak, 2015/01/16 07:10:39]

Done.

+    // char_index.
+    selection_[last].SetCharCount(-(selection_[last].char_index() + 1));
 
     // First make sure that there are no gaps in selection, i.e. if mousedown on
     // page three but we only get mousemove over page one, we want page two.