The following revision refers to this bug:
  https://pdfium.googlesource.com/pdfium/+/217644c0d65abfc9729c083074d505b22cd7ccf6

commit 217644c0d65abfc9729c083074d505b22cd7ccf6
Author: Nicolas Pena <npm@chromium.org>
Date: Mon Jul 10 14:33:02 2017

Force unicodes into valid ranges

U+D800 to U+DFFF should not be encoded in UTF-16. However, FreeType may
have charcodes in that range, so in that case we just say that the
corresponding unicode is U+0000, NULL.

Bug:  chromium:732272 
Change-Id: I64e82856bab7f69545a307da1fef4df7f9df1f00
Reviewed-on: https://pdfium-review.googlesource.com/7312
Commit-Queue: Nicolás Peña <npm@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

[modify] https://crrev.com/217644c0d65abfc9729c083074d505b22cd7ccf6/fpdfsdk/fpdfedittext.cpp

ClusterFuzz has detected this issue as fixed in range 485271:485338.

Detailed report: https://clusterfuzz.com/testcase?key=5713866469408768

Fuzzer: libFuzzer_pdf_font_fuzzer
Job Type: libfuzzer_chrome_asan_debug
Platform Id: linux

Crash Type: ASSERT
Crash Address: 
Crash State:
  unicode <= ADDRESS || (unicode > ADDRESS && unicode <= ADDRESS)
  FXSYS_ToUTF16BE
  AddUnicode
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_asan_debug&range=472896:472939
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_asan_debug&range=485271:485338

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5713866469408768


See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

ClusterFuzz testcase 5713866469408768 is verified as fixed, so closing issue.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.