Fix handling of UTF16-LE annotations (#558) · Issues · poppler / poppler

Fix handling of UTF16-LE annotations

Submitted by Christophe Fergeau `@teuf`

Assigned to poppler-bugs

Description

Created attachment 134538 Test case

The 'unicode' annotation in the attached test case does not render properly. I added it through the default mail application on my iOS11 iphone. I trade that down to _poppler_goo_string_to_utf8() which assumes UTF16 strings will always be big endian, while in my test file, a little endian UTF16 string is used. I've fixed this by adding 2 new methods to GooString (hasBigEndianBOM() hasLittleEndianBOM()), but all users of GooString::hasUnicodeMarker() should probably be audited and handle both types of UTF16 strings unless the pdf specs mandates big endian strings. Since I'm not familiar at all with the PDF format, I haven't tried to address this yet.

Attachment 134538, "Test case":
poppler-utf16-le.pdf

## Submitted by Christophe Fergeau `@teuf`  
Assigned to **poppler-bugs**

**[Link to original bug (#103023)](https://bugs.freedesktop.org/show_bug.cgi?id=103023)**  
## Description
Created attachment 134538
Test case

The 'unicode' annotation in the attached test case does not render properly. I added it through the default mail application on my iOS11 iphone.
I trade that down to _poppler_goo_string_to_utf8() which assumes UTF16 strings will always be big endian, while in my test file, a little endian UTF16 string is used.
I've fixed this by adding 2 new methods to GooString (hasBigEndianBOM() hasLittleEndianBOM()), but all users of GooString::hasUnicodeMarker() should probably be audited and handle both types of UTF16 strings unless the pdf specs mandates big endian strings. Since I'm not familiar at all with the PDF format, I haven't tried to address this yet.
  
**Attachment 134538**, "Test case":  
[poppler-utf16-le.pdf](/uploads/ea9109513c4071675495ad777343ce6a/poppler-utf16-le.pdf)

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