Avoid endless loop deleting CFGAS_GEFont.

It's a ref-counted class, so if we're in the destructor, the ref
count has hit zero. We can't make a new ref pointer to itself here,
as it will re-invoke the destructor when it goes out of scope. This
should have been an obvious anti-pattern in hindsight.

The object in question can't be in the m_pFontManager, since the font
manager retains a reference, and we wouldn't get to this destructor
while that is present. So the cleanup isn't required.

Fixing this revealed a free-delete mismatch in cxfa_textlayout.cpp.
I also converted to use unique_ptrs in a few places near this issue.

Fixing this revealed a UAF in CFGAS_GEFont, memcpy'ing a RetainPtr
is not a good idea as it doesn't bump the ref count.

Also protect and friend the CFGAS_GEFont destructor, to make sure
random deletes don't happen.

Also kill off a const cast, and remove unnecessary conversion to
retain_ptr when we already have one.

TEST=look for absence of -11 in XFA corpus test logs, bots not
     currently noticing the segv.  Argh.

Review-Url: https://codereview.chromium.org/2631703003

1 files changed, 1 insertions, 1 deletions

diff --git a/xfa/fde/cfde_txtedtengine.cpp b/xfa/fde/cfde_txtedtengine.cpp
index 8bb944712a..7ef6b3ff06 100644
--- a/xfa/fde/cfde_txtedtengine.cpp
+++ b/xfa/fde/cfde_txtedtengine.cpp
@@ -84,7 +84,7 @@ void CFDE_TxtEdtEngine::SetEditParams(const FDE_TXTEDTPARAMS& params) {
   if (!m_pTextBreak)
     m_pTextBreak = pdfium::MakeUnique<CFX_TxtBreak>(FX_TXTBREAKPOLICY_None);
 
-  FXSYS_memcpy(&m_Param, &params, sizeof(FDE_TXTEDTPARAMS));
+  m_Param = params;
   m_wLineEnd = params.wLineBreakChar;
   m_bAutoLineEnd = (m_Param.nLineEnd == FDE_TXTEDIT_LINEEND_Auto);
   UpdateTxtBreak();