The count of a SubFileDecode filter bounds what it passes through, not
what it allocates, but the reader refused counts over 4 MiB as a
rangecheck. Ghostscript's eps2write files read each content stream with
currentfile Length () /SubFileDecode filter, so a page whose stream is
longer than 4 MiB failed to open.
`eexec` dropped its file operand and skipped the encrypted part of a
font program to `cleartomark` in the program's own file. With
`currentfile eexec` inside a file run with `cvx exec`, the program goes
on in that file, so the skip searched the outer file instead and failed
or skipped the wrong text. Ghostscript's eps2write runs each embedded
Type 1 font program that way, so an EPS with one did not open.
`eexec` now skips in its operand, through the same file reading as the
other data operators: the program's own file or the file being run. A
string operand skips in the file being read, as before.
A filter over `currentfile` waits until it is first read, and it took
its data from whichever file was running by then. One made over the
program's own file and first read inside a file run with `cvx exec`
read that file instead, and one made over a file being run, first read
in a file that one runs, read the inner file. The pending stream now
records the file it was made over (a chained filter inherits it), and
`materialize` decodes from that file.
A file run with `cvx exec` was read whole and run as a separate
program, while `currentfile` stayed the outer EPS. The PLRM has
`currentfile` return the topmost file being run, positioned after the
last token read. Ghostscript's eps2write runs each page's content and
each Type 3 glyph from a SubFileDecode filter, and its `ID` reads the
inline image's samples through `currentfile`, so they were read from
the outer file and then ran as program.
A file being run is now read object by object from its own data, and
while it runs it is `currentfile`. A filter made over it waits to
read, as one over the program's own file does, so it starts where the
program is when the filter is first read.
Don Omondi