Fix backspace on 1st character of a line erases the line break.

Bug: chromium:836361
Change-Id: I39a0a3f9cb59ceb81f944dd5d0d4fd38a2e18a6b
Reviewed-on: https://pdfium-review.googlesource.com/31411
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>

2 files changed, 105 insertions, 5 deletions

diff --git a/xfa/fwl/cfwl_edit.cpp b/xfa/fwl/cfwl_edit.cpp
index afa9aac87d..8ebc155a80 100644
--- a/xfa/fwl/cfwl_edit.cpp
+++ b/xfa/fwl/cfwl_edit.cpp
@@ -1252,7 +1252,7 @@ void CFWL_Edit::OnChar(CFWL_MessageKey* pMsg) {
   switch (c) {
     case L'\b':
       if (m_CursorPosition > 0) {
-        SetCursorPosition(m_EdtEngine.GetIndexBefore(m_CursorPosition));
+        SetCursorPosition(m_CursorPosition - 1);
         m_EdtEngine.Delete(m_CursorPosition, 1);
       }
       break;
diff --git a/xfa/fwl/cfwl_edit_embeddertest.cpp b/xfa/fwl/cfwl_edit_embeddertest.cpp
index 7415e05845..ecc3b5ed13 100644
--- a/xfa/fwl/cfwl_edit_embeddertest.cpp
+++ b/xfa/fwl/cfwl_edit_embeddertest.cpp
@@ -8,13 +8,13 @@
 #include "testing/embedder_test.h"
 #include "testing/embedder_test_timer_handling_delegate.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "testing/xfa_js_embedder_test.h"
 
-class CFWLEditEmbeddertest : public EmbedderTest {
+class CFWLEditEmbeddertest : public XFAJSEmbedderTest {
  protected:
   void SetUp() override {
     EmbedderTest::SetUp();
     SetDelegate(&delegate_);
-    CreateAndInitializeFormPDF();
   }
 
   void TearDown() override {
@@ -22,8 +22,8 @@ class CFWLEditEmbeddertest : public EmbedderTest {
     EmbedderTest::TearDown();
   }
 
-  void CreateAndInitializeFormPDF() {
-    EXPECT_TRUE(OpenDocument("xfa/email_recommended.pdf"));
+  void CreateAndInitializeFormPDF(const char* filename) {
+    EXPECT_TRUE(OpenDocument(filename));
     page_ = LoadPage(0);
     ASSERT_TRUE(page_);
   }
@@ -37,10 +37,12 @@ class CFWLEditEmbeddertest : public EmbedderTest {
 };
 
 TEST_F(CFWLEditEmbeddertest, Trivial) {
+  CreateAndInitializeFormPDF("xfa/email_recommended.pdf");
   ASSERT_EQ(0u, delegate().GetAlerts().size());
 }
 
 TEST_F(CFWLEditEmbeddertest, LeftClickMouseSelection) {
+  CreateAndInitializeFormPDF("xfa/email_recommended.pdf");
   FORM_OnLButtonDown(form_handle(), page(), 0, 115, 58);
   for (size_t i = 0; i < 10; ++i)
     FORM_OnChar(form_handle(), page(), 'a' + i, 0);
@@ -58,6 +60,7 @@ TEST_F(CFWLEditEmbeddertest, LeftClickMouseSelection) {
 }
 
 TEST_F(CFWLEditEmbeddertest, DragMouseSelection) {
+  CreateAndInitializeFormPDF("xfa/email_recommended.pdf");
   FORM_OnLButtonDown(form_handle(), page(), 0, 115, 58);
   for (size_t i = 0; i < 10; ++i)
     FORM_OnChar(form_handle(), page(), 'a' + i, 0);
@@ -72,4 +75,101 @@ TEST_F(CFWLEditEmbeddertest, DragMouseSelection) {
   unsigned short buf[128];
   unsigned long len = FORM_GetSelectedText(form_handle(), page(), &buf, 128);
   EXPECT_STREQ(L"defgh", WideString::FromUTF16LE(buf, len).c_str());
+
+  // TODO(hnakashima): This is incorrect. Visually 'abcdefgh' are selected.
+  const char kDraggedMD5[] = "69c13fe53b5fc422ebeab56d101a4658";
+  {
+    ScopedFPDFBitmap page_bitmap =
+        RenderPageWithFlags(page(), form_handle(), FPDF_ANNOT);
+    CompareBitmap(page_bitmap.get(), 612, 792, kDraggedMD5);
+  }
+}
+
+TEST_F(CFWLEditEmbeddertest, SimpleFill) {
+  CreateAndInitializeFormPDF("xfa/email_recommended.pdf");
+  const char kBlankMD5[] = "eea5c72701270ac4a7edcc4df66d812a";
+  {
+    ScopedFPDFBitmap page_bitmap =
+        RenderPageWithFlags(page(), form_handle(), FPDF_ANNOT);
+    CompareBitmap(page_bitmap.get(), 612, 792, kBlankMD5);
+  }
+
+  FORM_OnLButtonDown(form_handle(), page(), 0, 115, 58);
+  for (size_t i = 0; i < 10; ++i)
+    FORM_OnChar(form_handle(), page(), 'a' + i, 0);
+
+  const char kFilledMD5[] = "e73263fcea46c18d874b3d5a79f53805";
+  {
+    ScopedFPDFBitmap page_bitmap =
+        RenderPageWithFlags(page(), form_handle(), FPDF_ANNOT);
+    CompareBitmap(page_bitmap.get(), 612, 792, kFilledMD5);
+  }
+}
+
+TEST_F(CFWLEditEmbeddertest, FillWithNewLineWithoutMultiline) {
+  CreateAndInitializeFormPDF("xfa/email_recommended.pdf");
+  FORM_OnLButtonDown(form_handle(), page(), 0, 115, 58);
+  for (size_t i = 0; i < 5; ++i)
+    FORM_OnChar(form_handle(), page(), 'a' + i, 0);
+  FORM_OnChar(form_handle(), page(), '\r', 0);
+  for (size_t i = 5; i < 10; ++i)
+    FORM_OnChar(form_handle(), page(), 'a' + i, 0);
+
+  const char kFilledMD5[] = "e73263fcea46c18d874b3d5a79f53805";
+  {
+    ScopedFPDFBitmap page_bitmap =
+        RenderPageWithFlags(page(), form_handle(), FPDF_ANNOT);
+    CompareBitmap(page_bitmap.get(), 612, 792, kFilledMD5);
+  }
+}
+
+// Disabled due to flakiness.
+TEST_F(CFWLEditEmbeddertest, DISABLED_FillWithNewLineWithMultiline) {
+  CreateAndInitializeFormPDF("xfa/xfa_multiline_textfield.pdf");
+  FORM_OnLButtonDown(form_handle(), page(), 0, 115, 58);
+
+  for (size_t i = 0; i < 5; ++i)
+    FORM_OnChar(form_handle(), page(), 'a' + i, 0);
+  FORM_OnChar(form_handle(), page(), '\r', 0);
+  for (size_t i = 5; i < 10; ++i)
+    FORM_OnChar(form_handle(), page(), 'a' + i, 0);
+
+  // Should look like:
+  // abcde
+  // fghij|
+  {
+#if _FX_PLATFORM_ == _FX_PLATFORM_LINUX_
+    const char kFilledMultilineMD5[] = "fc1f4d5fdb2c5755005fc525b0a60ec9";
+#else
+    const char kFilledMultilineMD5[] = "a5654e027d8b1667c20f3b86d1918003";
+#endif  // _FX_PLATFORM_ == _FX_PLATFORM_LINUX_
+    ScopedFPDFBitmap page_bitmap =
+        RenderPageWithFlags(page(), form_handle(), FPDF_ANNOT);
+    CompareBitmap(page_bitmap.get(), 612, 792, kFilledMultilineMD5);
+  }
+
+  for (size_t i = 0; i < 4; ++i)
+    FORM_OnKeyDown(form_handle(), page(), FWL_VKEY_Left, 0);
+
+  // Should look like:
+  // abcde
+  // f|ghij
+
+  // Two backspaces is a workaround because left arrow does not behave well
+  // in the first character of a line. It skips back to the previous line.
+  for (size_t i = 0; i < 2; ++i)
+    FORM_OnChar(form_handle(), page(), '\b', 0);
+
+  // Should look like:
+  // abcde|ghij
+  {
+#if _FX_PLATFORM_ == _FX_PLATFORM_LINUX_
+    const char kMultilineBackspaceMD5[] = "8bb62a8100ff1e1cc113d4033e0d824e";
+#else
+    const char kMultilineBackspaceMD5[] = "a2f1dcab92bb1fb7c2f9ccc70100c989";
+#endif  // _FX_PLATFORM_ == _FX_PLATFORM_LINUX_
+    ScopedFPDFBitmap page_bitmap =
+        RenderPageWithFlags(page(), form_handle(), FPDF_ANNOT);
+    CompareBitmap(page_bitmap.get(), 612, 792, kMultilineBackspaceMD5);
+  }
 }