- Added JPEG texture support, courtesy of Ken's Picture Library. I will

probably switch to the IJG library once I pare it down. (Ken's code is 18K
  of C source but does not support progressive JPEG. The IJG library is over
  a megabyte of source and supports pretty much everything you would ever
  need ever.)
- Fixed endianness issue in FTextureManager::CreateTexture().
- Added support for interlaced PNGs. Now ZDoom is a mostly complete PNG
  reader. The only thing missing is 48-bit RGB and 16-bit grayscale support,
  which are just wastes of bits here, but also less likely to appear than
  an interlaced PNG. (However, if you are using interlaced PNGs for textures,
  then you are needlessly wasting space, since the image won't display
  progressively.)
- Fixed: Writing named screenshots didn't work.

SVN r292 (trunk)

src/m_misc.cpp

@@ -537,14 +537,14 @@ static BOOL FindFreeName (FString &fullname, const char *extension)
 	return false;
 }
 
-void M_ScreenShot (char *filename)
+void M_ScreenShot (const char *filename)
 {
 	FILE *file;
 	FString autoname;
 	bool writepcx = (stricmp (screenshot_type, "pcx") == 0);	// PNG is the default
 
 	// find a file name to save it to
-	if (filename == NULL)
+	if (filename == NULL || filename[0] == '\0')
 	{
 #ifndef unix
 		if (Args.CheckParm ("-cdrom"))