Hi, In OpenType fonts, SVG documents can be either in plain text or gzip encoded.
While writing the code to read these documents I looked for a function which could do gzip decoding inside FreeType. That's when I found `FT_Gzip_Uncompress'. Using it, I realized it didn't work as expected and returned errors. After using zlib in a separate program on the same data I figured out the problem. Zlib data can be encoded with both `gzip' and `zlib' encoded wrapper. AFAIK, by default, it looks for only `zlib' wrapper. The current call to `inflateInit2' is: 749| err = inflateInit2( &stream, MAX_WBITS ); > > `MAX_WBITS' is 15. Thus, it only looks for `zlib' wrapper and in case of gzip compressed SVGs, returns error when `inflate' is called. The fix is to replace it with: 749| err = inflateInit2( &stream, MAX_WBITS|32 ); > > This enables both `gzip' and `zlib' decoding with automatic header detection. Solving my problem. I am quoting the relevant section from zlib's manual for reference. Can be seen here <https://www.zlib.net/manual.html>: windowBits can also be greater than 15 for optional gzip decoding. Add 32 > to windowBits to enable zlib and gzip decoding with automatic header > detection, or add 16 to decode only the gzip format (the zlib format will > return a Z_DATA_ERROR). This solves it for me and I HOPE this won't cause cause any previous code relying on `FT_Gzip_Uncompress' to fail. Let me know if there are easy tests to check that. Let me know if this is the right change and can also be made in master later on, meaning I can rely on it. :) Moazin
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