Name: yyT116575 Date: 12/14/2000


java version "1.3.0_01"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0_01)
Java HotSpot(TM) Client VM (build 1.3.0_01, mixed mode)

1. Obtain a "bad" jpeg file (vague definition, but don't worry)
2. Call JPEGImageDecoder.decodeAsBufferedImage() with an InputStream pointing at
the bad jpeg file.
3. Observe the error message: "2 extraneous bytes before marker 0xd9"
4. Note that the routine never completes, and that CPU use moves to 100%, which
seems to indicate an infinite loop problem.

Further investigation revealed the problem to be in libjpeg.so, file
jpegimagedecoderimpl.c, function "cleanup", on or about line 690 (assumes the
JDK 1.2.2 source), which repeatedly calls InputStream.skip(x) until it is told
that "x" bytes were actually skipped. From what I can tell, in my problem case,
the InputStream returns 0 skipped bytes, so this loop continues forever.

To test my theory, I added some code to drop out of the loop when
InputStream.skip(x) returns <= 0, installed my modified libjpeg.so, and retried
my "bad jpeg" test case. Result: no more infinite loop. Eyeball the code and
hopefully this fix makes sense to you as well.

A parenthetical remark: I could not have found this problem without
your "community source" program.
(Review ID: 113780)
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