[FIXED JENKINS-23410]

Integrated the fix made in winp 1.20.

(cherry picked from commit fad3f7db48e4184221469fbbb0edc2163e26ac0f)
[JENKINS-17374 JENKINS-18116] Don't set gzip header for error

(cherry picked from commit 0a241aafdbdf3ad15d34efa3077658c5770b9195)
[JENKINS-22395]

I'm not sure if I understand how the original fix in PR #1190 (f1430a2) addresses the problem.

My understanding is of the problem is as follows:

  - someone deletes 'b2' but holds on to its reference (could be different threads)
  - someone calls b2.getPreviousBuild()
    - if b2.previousBuildR is null, then this triggers the loading of b1, and
      that process sets up a bi-di link via b1<->b2 via b1.nextBuildR <-> b2.previousBuildR
    - this makes b1.getNextBuild() incorrectly return b2

Presumably f1430a2 addresses this somehow, but I think I can induce this situation in other ways,
which is what dropLinksAfterGC2() does.

In this test,

initial state:

   b1 <-> b2 <-> b3

   we load everyone and connect them all up

after deleting b2:

   b1 <--------> b3
    ^            ^
    +---- b2 ----+

  b1 and b3 points each other, and b2 still refers to each side

after dropping b1:

          b2 --> b3

now, here, when I do b2.getPreviousBuild(), it loads b1a and it sets b1a.nextBuildR to b2.

    b1a <-> b2 --> b3

So I claim this is a proof that the fix is incomplete, even for the problem JENKINS-22395 has discovered.

I don't think that the problem is for the dropLinks call to fail to patch up references.
The problem is that b2.getPreviousBuild() forcing b1 to point to b2, because if b2 is deleted and assumed to be
invalid, then no matter what bX this method will find you never want bX.nextBuildR to point to b2.

(cherry picked from commit 53e95ee517259e1e10d7209bcbaa4314397c1f40)
[JENKINS-22395] correcting the control test

As I step-executed the code, I discovered b2.getPreviousBuild() was getting invoked
between BRHF.drop(b1) and b2.dropLinks() call, in PeepholePermalink.RunListenerImpl.onDeleted()
because Run.delete() calls RunListener.fireDeleted(this).

Thus in effect the sequence of the call order was as follows:

        assertEquals(1, BRHF.drop(b1));
        b2.getPreviousBuild(); // happens indirectly in PeepholePermalink
        b2.delete();
        FreeStyleBuild b1a = b2.getPreviousBuild();

This defeats the purpose of the fix, because in this call sequence, by b2.dropLinks()
as implemented before f1430a2 will correctly fix up b1a.nextBuildR to b3.

For the test to work as intended, it is important that b2.previousBuildR.get()==null
during dropLinks(). That is what causes b2.getPreviousBuild() in the next line to go
load b1a, and sets up b1a.nextBuildR to b2, and trigger the assertion error.

Added a code to remove all RunListeners. With this change, the test now fails without
the fix in f1430a2.

(cherry picked from commit 7b1b50c85a6a4bdb75f1ae5b40885afa45f96b82)
[FIXED JENKINS-22395] redoing the fix in f1430a2

Based on the last few commits, I proved that the original fix in f1430a2
doesn't really address the problem.

That is, once b2 is deleted, and after sufficient garbage collection,
we can make b2.previousBuild.get() be null, and then
b2.getPreviousBuild().getNextBuild() ends up incorrectly returning b2.

In this commit, I roll back that part of f1430a2, and then fix the
problem differently.

I started thinking that the main problem we are trying to fix here
is that the deleted build object should be unreferenceable. That is,
it should behave almost as if the object has already been GCed.
The easiest way to do this is to clear a BuildReference object,
since we always use the same BuildReference object for all inbound
references.

This change allows us to clear BuildReference. Code like
b2.getPreviousBuild() will continue to try to update
b1.nextBuildR to b2, but it will only end up wiping out the field,
only to have b1.getNextBuild() recompute the correct value.

This fix makes both test cases pass in LazyBuildMixInTest.

(cherry picked from commit b6226ad2d1a332cb661ceb5c5f5b673771118e14)
[JENKINS-22395] more diagnostics

Just in case the previous fix didn't address the root cause of ZD-11985 (and given the time it takes for changes like this to land in LTS), I'm adding additional diagnostics that let us track how previous/next builds are getting discovered

(cherry picked from commit aa8e0b4f0e312ba4ef9c647ccf2c093793a9bece)
[JENKINS-22395] Taking advantage of BuildReference.clear (just introduced in b6226ad) to simplify test by not requiring a custom build reference holder just to simulate GC.
Confirmed that dropLinksAfterGC and dropLinksAfterGC2 both fail in the expected way (b1a.nextBuild == b2) after commenting out the call to createReference().clear() in dropLinks.
(Also that they fail as expected in assertNotSame if the reference is not cleared at all.)

(cherry picked from commit b7ec8578f938864af9c8dbfb73a54d67f972d694)
[FIXED JENKINS-18065] made ALLRM.entrySet() smarter

(cherry picked from commit 54c084613f83f9b7a02957eb98dbd8dc661d1c9c)

Conflicts:
	changelog.html
[JENKINS-18065] 54c0846 amendment: presumably RunMap.entrySet().iterator().next().setValue(…) should be illegal.
(cherry picked from commit da57ad5c30b1c9ca8365f869638abd29c8fb5896)
[JENKINS-18065] Uncommenting original test.
The actual implementation does not behave as nicely as one would hope, for a few reasons:
1. isEmpty actually tries to load the newestBuild, rather than simply checking whether there is some idOnDisk.
   Arguably this is necessary, since there could be an unloadable build record, in which case it would be technically correct for the map to be considered empty.
2. Loading AbstractLazyLoadRunMap.newestBuild calls search(MAX_VALUE, DESC), which behaves oddly, by doing a binary search, and thus perhaps loading lg(|map|) entries.
   You would think that it would suffice to check for the last member of idOnDisk in index.byId.
3. The iterator eagerly loads the next value before hasNext has even been called.
   Looks bad in a test, though it probably has little practical impact since most callers would be calling hasNext soon afterward anyway.
   Might cause one extra build record to be loaded unnecessarily from a limited RunList.

(cherry picked from commit 2f58ceb1a66c8ed621fa2562c5ed3445b29ea200)
[FIXED JENKINS-20663] For now, go back to using ZipOutputStream from Ant that supports setting the filename encoding (present in java.util.zip only in Java 7+).
(cherry picked from commit 84c76253862a2f36f813a7aa45b77d99c1616be4)

Conflicts:
	changelog.html
Do not mix old and new test-annotations libraries.
Corrects 9ce6b0fec3c0a0f1b9ea786865b2130a900a5886.
(cherry picked from commit 032a47599d63a38d499b8f015dc57b2d41419130)