Fix the TrueType font not rendered correctly issue.
This CL removes the extra check on whether no glyph index is found for
a TrueType font character in CPDF_SimpleFont::GlyphFromCharCode(), so
that whenever CPDF_SimpleFont::GlyphFromCharCode() returns -1, it
indicates a guaranteed failure and we can handle the TrueType font
later on in CPDF_CharPosList::CPDF_CharPosList().
If a TrueType font fails to find glyph index, i.e. when
CPDF_SimpleFont::GlyphFromCharCode() returns 0, we should first try to
find the glyph index from the fallback font. If that fails, switch back
to use the original font.
Bug: pdfium:1388
Change-Id: I8b1935a094f76408e4678723d566914c2bbf0f42
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/60091
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
diff --git a/core/fpdfapi/font/cpdf_simplefont.cpp b/core/fpdfapi/font/cpdf_simplefont.cpp
index cff773a..9371678 100644
--- a/core/fpdfapi/font/cpdf_simplefont.cpp
+++ b/core/fpdfapi/font/cpdf_simplefont.cpp
@@ -47,7 +47,7 @@
return -1;
int index = m_GlyphIndex[charcode];
- if (index == 0xffff || (index == 0 && IsTrueTypeFont()))
+ if (index == 0xffff)
return -1;
return index;
diff --git a/core/fpdfapi/render/cpdf_charposlist.cpp b/core/fpdfapi/render/cpdf_charposlist.cpp
index 7fc1e24..13ef124 100644
--- a/core/fpdfapi/render/cpdf_charposlist.cpp
+++ b/core/fpdfapi/render/cpdf_charposlist.cpp
@@ -19,6 +19,7 @@
m_CharPos.reserve(charCodes.size());
CPDF_CIDFont* pCIDFont = pFont->AsCIDFont();
bool bVertWriting = pCIDFont && pCIDFont->IsVertWriting();
+ bool bToUnicode = !!pFont->GetFontDict()->GetStreamFor("ToUnicode");
for (size_t i = 0; i < charCodes.size(); ++i) {
uint32_t CharCode = charCodes[i];
if (CharCode == static_cast<uint32_t>(-1))
@@ -39,19 +40,41 @@
? charpos.m_ExtGID
: charpos.m_GlyphIndex;
#endif
- CFX_Font* pCurrentFont;
- if (GlyphID != static_cast<uint32_t>(-1)) {
- charpos.m_FallbackFontPosition = -1;
- pCurrentFont = pFont->GetFont();
- } else {
+ bool bIsInvalidGlyph = GlyphID == static_cast<uint32_t>(-1);
+ bool bIsTrueTypeZeroGlyph = GlyphID == 0 && pFont->IsTrueTypeFont();
+ bool bUseFallbackFont = false;
+ if (bIsInvalidGlyph || bIsTrueTypeZeroGlyph) {
charpos.m_FallbackFontPosition =
pFont->FallbackFontFromCharcode(CharCode);
charpos.m_GlyphIndex = pFont->FallbackGlyphFromCharcode(
charpos.m_FallbackFontPosition, CharCode);
+ if (bIsTrueTypeZeroGlyph &&
+ charpos.m_GlyphIndex == static_cast<uint32_t>(-1)) {
+ // For a TrueType font character, when finding the glyph from the
+ // fallback font fails, switch back to using the original font.
+
+ // When keyword "ToUnicode" exists in the PDF file, it indicates
+ // a "ToUnicode" mapping file is used to convert from CIDs (which
+ // begins at decimal 0) to Unicode code. (See ToUnicode Mapping File
+ // Tutorial - Adobe
+ // https://www.adobe.com/content/dam/acom/en/devnet/acrobat/pdfs/5411.ToUnicode.pdf
+ // and
+ // https://www.freetype.org/freetype2/docs/tutorial/step1.html#section-6)
+ if (bToUnicode)
+ charpos.m_GlyphIndex = 0;
+ } else {
+ bUseFallbackFont = true;
+ }
+ }
+ CFX_Font* pCurrentFont;
+ if (bUseFallbackFont) {
pCurrentFont = pFont->GetFontFallback(charpos.m_FallbackFontPosition);
#if defined(OS_MACOSX)
charpos.m_ExtGID = charpos.m_GlyphIndex;
#endif
+ } else {
+ pCurrentFont = pFont->GetFont();
+ charpos.m_FallbackFontPosition = -1;
}
if (!pFont->IsEmbedded() && !pFont->IsCIDFont())
diff --git a/testing/SUPPRESSIONS b/testing/SUPPRESSIONS
index beca1be..2edcc57 100644
--- a/testing/SUPPRESSIONS
+++ b/testing/SUPPRESSIONS
@@ -331,9 +331,6 @@
# TODO(pdfium:1331): Remove after associated bug is fixed
bug_1331.in * * *
-# TODO(pdfium:1388): Remove after associated bug is fixed
-bug_1388.in * * *
-
# xfa_specific
# TODO(pdfium:1107): Remove after associated bug is fixed
