Fix JPEG2000 decoding when there is no /ColorSpace.

Bug: pdfium:304,pdfium:1490
Change-Id: I85ac40a3d802a3e184e3e5a78ca7697b1624a42a
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/67755
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

core/fpdfapi/page/cpdf_dib.cpp

diff --git a/core/fpdfapi/page/cpdf_dib.cpp b/core/fpdfapi/page/cpdf_dib.cpp
index 6b19730..f2d78d7 100644
--- a/core/fpdfapi/page/cpdf_dib.cpp
+++ b/core/fpdfapi/page/cpdf_dib.cpp
@@ -929,6 +929,11 @@
   // Per spec, |m_bpc| should always be 8 for RunLengthDecode, but too many
   // documents do not conform to it. So skip this check.
 
+  if (filter == "JPXDecode") {
+    m_bDoBpcCheck = false;
+    return;
+  }
+
   if (filter == "CCITTFaxDecode" || filter == "JBIG2Decode") {
     m_bpc = 1;
     m_nComponents = 1;

testing/SUPPRESSIONS

diff --git a/testing/SUPPRESSIONS b/testing/SUPPRESSIONS
index 5aab61e..aefc38c 100644
--- a/testing/SUPPRESSIONS
+++ b/testing/SUPPRESSIONS
@@ -325,9 +325,6 @@
 #
 bug_492.in * nov8 *
 
-# TODO(pdfium:304): Remove after associated bug is fixed
-bug_304.pdf * * *
-
 # TODO(pdfium:1331): Remove after associated bug is fixed
 bug_1331.in * * *