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| author | Lei Zhang <leizleiz@users.noreply.github.com> | 2016-10-19 14:49:00 -0700 |
|---|---|---|
| committer | Lei Zhang <leizleiz@users.noreply.github.com> | 2016-10-19 14:49:00 -0700 |
| commit | 8475d2fd5f1ee4c734ea900c88283365a2f0dc87 (patch) | |
| tree | a170bfe79575a72d931da22b46dcb96d188b3bf6 | |
| parent | 1fba3b37c98301e2c01a5a3a7a87693ecdf4b4c8 (diff) | |
| download | sfntly-8475d2fd5f1ee4c734ea900c88283365a2f0dc87.tar.gz | |
Avoid NULL derefs inside FontHeaderTable::Builder.
As a result IndexToLocFormat() should also return an invalid value.
Fixes https://crbug.com/646347
| -rw-r--r-- | cpp/src/sfntly/table/core/font_header_table.cc | 5 | ||||
| -rw-r--r-- | cpp/src/sfntly/table/core/font_header_table.h | 1 | ||||
| -rw-r--r-- | cpp/src/sfntly/table/table_based_table_builder.cc | 6 |
3 files changed, 9 insertions, 3 deletions
diff --git a/cpp/src/sfntly/table/core/font_header_table.cc b/cpp/src/sfntly/table/core/font_header_table.cc index 60015ca..a848afd 100644 --- a/cpp/src/sfntly/table/core/font_header_table.cc +++ b/cpp/src/sfntly/table/core/font_header_table.cc @@ -239,7 +239,10 @@ void FontHeaderTable::Builder::SetFontDirectionHint(int32_t hint) { } int32_t FontHeaderTable::Builder::IndexToLocFormat() { - return down_cast<FontHeaderTable*>(GetTable())->IndexToLocFormat(); + Table* table = GetTable(); + if (!table) + return IndexToLocFormat::kInvalidOffset; + return down_cast<FontHeaderTable*>(table)->IndexToLocFormat(); } void FontHeaderTable::Builder::SetIndexToLocFormat(int32_t format) { diff --git a/cpp/src/sfntly/table/core/font_header_table.h b/cpp/src/sfntly/table/core/font_header_table.h index 841955b..4851775 100644 --- a/cpp/src/sfntly/table/core/font_header_table.h +++ b/cpp/src/sfntly/table/core/font_header_table.h @@ -24,6 +24,7 @@ namespace sfntly { struct IndexToLocFormat { enum { + kInvalidOffset = -1, kShortOffset = 0, kLongOffset = 1 }; diff --git a/cpp/src/sfntly/table/table_based_table_builder.cc b/cpp/src/sfntly/table/table_based_table_builder.cc index b505704..51a5a3b 100644 --- a/cpp/src/sfntly/table/table_based_table_builder.cc +++ b/cpp/src/sfntly/table/table_based_table_builder.cc @@ -60,8 +60,10 @@ TableBasedTableBuilder::TableBasedTableBuilder(Header* header) } Table* TableBasedTableBuilder::GetTable() { - if (table_ == NULL) { - table_.Attach(down_cast<Table*>(SubBuildTable(InternalReadData()))); + if (!table_) { + ReadableFontData* data = InternalReadData(); + if (data) + table_.Attach(down_cast<Table*>(SubBuildTable(data))); } return table_; } |