Manifest ignores last line if not terminated by line break

[Philipp Kunz]

Hi,

Manifest parsing an input stream given to the constructor or the read
method ignores the contents of the last line unless terminated with a
line break.

In course of my attempt to fix 8217375, I found that Manifest ignores
the last line when not terminated with a line break whereas
ManifestDigester throws an exception.
Without ManifestDigester's different behavior, I'd have opted for
parsing the last line also without a line break (or the last line being
empty).
But ManifestDigester cannot easily be changed that way, too, because
the line breaks are part of the digested manifest portions.
I don't think Manifest should accept any manifests that cannot later as
well be signed and should therefore raise an error when there is no
line break at the end of a manifest.
Adding a new error condition adds potential for compatibility issues.
On the other hand, I don't think the last 'ill'-terminated line should
really be ignored silently.
A good example how things can go wrong this way is
JavaClassPathTest.java. It uses a one-line manifest without a trailing
line break and m1.jar does not contain the expected Class-Path entry.
In the long term the best option would probably be to re-unite
Manifest's and ManifestDigester's parsing-related code the biggest
challenge of which is not to change digests and thereby break existing
jar signatures.

Attached is a patch with a proposed fix.

The bug number in
test/jdk/java/util/jar/Manifest/NoLineBreakAtEndOfManifestFile.java is
from another bug that lead me to it. If someone creates another bug it
can be replaced. I haven't found an existing issue that matches.
In test/jdk/tools/launcher/modules/classpath/JavaClassPathTest.java is
a test case testJARManifestClassPathAttribute/testClassPathAttribute
which I have no clue how this should really work. As far as I can tell
the test is and was wrong but nevertheless passes.

Is there a chance to find a sponsor for fixing this?

Regards,
Philipp
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