Fix caret moving to next line upon click on line break in XFA edit.

Bug: chromium:836361
Change-Id: I40739a21a60610bd5ab0143629f87562ba834a0d
Reviewed-on: https://pdfium-review.googlesource.com/31410
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>
diff --git a/xfa/fde/cfde_texteditengine.cpp b/xfa/fde/cfde_texteditengine.cpp
index 989843c..0157b35 100644
--- a/xfa/fde/cfde_texteditengine.cpp
+++ b/xfa/fde/cfde_texteditengine.cpp
@@ -941,13 +941,18 @@
     size_t pos = std::min(
         static_cast<size_t>(start_it->nStart + start_it->nCount), text_length_);
 
-    // The line is not the last one and it was broken right after a space, the
-    // cursor should not be placed after the space, but before it. If the
-    // cursor is moved after the space, it goes to the beginning of the next
-    // line.
+    // If the line is not the last one and it was broken right after a breaking
+    // whitespace (space or line break), the cursor should not be placed after
+    // the whitespace, but before it. If the cursor is moved after the
+    // whitespace, it goes to the beginning of the next line.
     bool is_last_line = (std::next(start_it) == text_piece_info_.end());
-    if (!is_last_line && pos > 0 && GetChar(pos - 1) == L' ')
-      --pos;
+    if (!is_last_line && pos > 0) {
+      wchar_t previous_char = GetChar(pos - 1);
+      if (previous_char == L' ' || previous_char == L'\n' ||
+          previous_char == L'\r') {
+        --pos;
+      }
+    }
 
     return pos;
   }
diff --git a/xfa/fde/cfde_texteditengine_unittest.cpp b/xfa/fde/cfde_texteditengine_unittest.cpp
index ab8e640..123d16c 100644
--- a/xfa/fde/cfde_texteditengine_unittest.cpp
+++ b/xfa/fde/cfde_texteditengine_unittest.cpp
@@ -445,10 +445,7 @@
   engine()->SetFontSize(10.0f);
   engine()->Insert(0, L"Hello\nWorld");
   EXPECT_EQ(0U, engine()->GetIndexForPoint({0.0f, 0.0f}));
-
-  // TODO(hnakashima): Should be 5U, caret is moving to next line.
-  EXPECT_EQ(6U, engine()->GetIndexForPoint({999999.0f, 0.0f}));
-
+  EXPECT_EQ(5U, engine()->GetIndexForPoint({999999.0f, 0.0f}));
   EXPECT_EQ(6U, engine()->GetIndexForPoint({0.0f, 10.0f}));
   EXPECT_EQ(11U, engine()->GetIndexForPoint({999999.0f, 9999999.0f}));
 }