commit ea020fde461302941562bce270e14f7a1db886f7
author Tom Sepez <tsepez@chromium.org> Fri Jan 17 19:53:20 2020 +0000
committer Chromium commit bot <commit-bot@chromium.org> Fri Jan 17 19:53:20 2020 +0000
tree 503d0aeb877288d28b8a2ad43b7d2148bb2cc58a
parent d70e275db0232ebed12e3c10f9f50ce0d8373695

Avoid CHECK() in CFDE_TextEditEngine.

Maintain invariant that the text length does not exceed the
character limit, even when toggling on/off limits and inserting
text in-between. Take the conservative approach of not truncating
pre-existing input when the limits are toggled back and forth.

Bug: pdfium:1458
Change-Id: Id064d9f54929d91dea5027a024fcaab40e4c55e4
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/65290
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

xfa/fde/cfde_texteditengine.cpp

diff --git a/xfa/fde/cfde_texteditengine.cpp b/xfa/fde/cfde_texteditengine.cpp
index b13699e..66c24d1 100644
--- a/xfa/fde/cfde_texteditengine.cpp
+++ b/xfa/fde/cfde_texteditengine.cpp
@@ -644,6 +644,7 @@
     return;
 
   has_character_limit_ = limit;
+  character_limit_ = std::max(character_limit_, text_length_);
   if (is_comb_text_)
     SetCombTextWidth();
 
@@ -656,7 +657,7 @@
 
   ClearOperationRecords();
 
-  character_limit_ = limit;
+  character_limit_ = std::max(limit, text_length_);
   if (is_comb_text_)
     SetCombTextWidth();
 

xfa/fde/cfde_texteditengine_unittest.cpp

diff --git a/xfa/fde/cfde_texteditengine_unittest.cpp b/xfa/fde/cfde_texteditengine_unittest.cpp
index 87e29aa..2089dff 100644
--- a/xfa/fde/cfde_texteditengine_unittest.cpp
+++ b/xfa/fde/cfde_texteditengine_unittest.cpp
@@ -161,6 +161,20 @@
   engine()->SetDelegate(nullptr);
 }
 
+TEST_F(CFDE_TextEditEngineTest, InsertToggleLimit) {
+  engine()->SetHasCharacterLimit(true);
+  engine()->Insert(0, L"Hello World");
+  engine()->SetCharacterLimit(5);
+  engine()->Insert(0, L"Not Inserted before ");
+  EXPECT_STREQ(L"Hello World", engine()->GetText().c_str());
+
+  engine()->SetHasCharacterLimit(false);
+  engine()->Insert(0, L"Inserted before ");
+  engine()->SetHasCharacterLimit(true);
+  engine()->Insert(0, L"Not Inserted before ");
+  EXPECT_STREQ(L"Inserted before Hello World", engine()->GetText().c_str());
+}
+
 TEST_F(CFDE_TextEditEngineTest, InsertSkipNotify) {
   engine()->SetHasCharacterLimit(true);
   engine()->SetCharacterLimit(8);