On 2017-10-02 19:24, Philipp Kunz wrote:
Hi,
While fixing JDK-6695402 I came across other related bugs to manifests
such as JDK-6372077, JDK-6202130, JDK-8176843, JDK-4842483, and
JDK-6443578 which all relate to manifest reading and writing.
Somewhere bug 7071055 is mentioned but I cannot find anywhere.
You cannot find JDK-7071055 since it's classified Confidential. I'm not
sure why, but it has been closed as a duplicate of JDK-6695402, so it
does not really matter.
I'm happy to see we've gotten such a thorough contributor! :-) Keep up
the good work.
/Magnus
Another group of bugs, JDK-6910466, JDK-4935610, and JDK-4271239
concern the mandatory manifest main attributes Manifest-Version or
Signature-Version and at first glance are duplicates. If you know of
more known bugs, not necessarily present in jira, I'd be glad to get
notified.
There are also some comments about utf handling and line breaking in
the code of Manifest:
http://hg.openjdk.java.net/jdk10/master/file/a0116bcc65b7/src/java.base/share/classes/java/util/jar/Attributes.java#l299
http://hg.openjdk.java.net/jdk10/master/file/a0116bcc65b7/src/java.base/share/classes/java/util/jar/Attributes.java#l327
http://hg.openjdk.java.net/jdk10/master/file/a0116bcc65b7/src/java.base/share/classes/java/util/jar/Attributes.java#l370
Furthermore, Attributes.map should declare appropriate type parameters:
http://hg.openjdk.java.net/jdk10/master/file/a0116bcc65b7/src/java.base/share/classes/java/util/jar/Attributes.java#l61
The specification would also require that `header names must not start
with _, - or "From"`
(http://docs.oracle.com/javase/7/docs/technotes/guides/jar/jar.html#Section-Specification)
but I would opt not to add this as a hard restriction because I guess
it can be assumed that such names are in use now after having been
working for years. A warning to a logger might be conceivable such as in
http://hg.openjdk.java.net/jdk10/master/file/a0116bcc65b7/src/java.base/share/classes/java/util/jar/Attributes.java#l424
Attribute values are never checked at all and invalid characters such
as line breaks are never detected except that when reading the
manifest again the values are cut off.
The tab character (U+0008) does not work in manifest values.
I suspect that there are also issues regarding the iteration order but
I haven't got a prove yet unlike for the other points above:
http://hg.openjdk.java.net/jdk10/master/file/a0116bcc65b7/src/java.base/share/classes/java/util/jar/Manifest.java#l54
There is duplicated or very similar code in Attributes and Manifest:
Attributes.write-Manifest.write-Attributes.writeMain and
Attributes.read-Manifest.read.
Resolving JDK-6202130 would have the additional benefit to be able to
view manifests with any utf-8 capable editor even if multi-byte
characters break across lines.
Fixing these issues individually looks like more complicated work than
fixing them all at once, I guess, also because of a very low current
test coverage. So I'd suggest to add some thorough tests along with
fixing these issues. But before I start I would like to get some
guidance, assistance or at least confirmation on how to proceed. I'm
new to open jdk and have submitted only one patch so far.
Is it ok to add tests for things that have worked before?
Is it ok to refactor duplicated code just for the added value to
reduce effort for testing?
I assume compatibility to and from existing manifests is the highest
priority, correct? This would also be the hard part in adding as
complete test coverage as possible. What would be acceptable criteria
to meet?
Why does Attributes not extend LinkedHashMap and why does Manifest not
extend HashMap? Any objection?
While I would not want to write code that looks slow or change more
than necessary one can never know before having performance actually
measured. Is there some way this is dealt with or should I wait for
such feedback until after patch submission?
Would someone sponsor?
Regards,
Philipp
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