allowing 0 for extent value

Backports PR #10528

**Commit 1:**
allowing 0 for extent value

* Original sha: 17f72c9
* Authored by ppisljar <peter.pisljar@gmail.com> on 2017-02-23T09:23:48Z

**Commit 2:**
fixing based on review

* Original sha: dbef23a
* Authored by ppisljar <peter.pisljar@gmail.com> on 2017-02-28T10:15:30Z

backport--instructions.rej

@@ -0,0 +1,83 @@
+Backport of PR #10528 to branch 5.2 failed
+
+https://github.com/elastic/kibana/pull/10528
+
+
+- 1 patch failed to apply
+- 1 patch was applied successfully
+
+-------------------------------------
+
+At this point, you need to manually resolve these conflicts on your machine and
+push the changes back up to this upstream branch so the PR is updated with your
+changes. The following instructions and scripts should help with that.
+
+All of the provided scripts assume that the remote "upstream" is where the
+backport branch exists and that your local branch has the exact same name as
+the upstream branch.
+
+First, check out this branch locally:
+
+  git fetch upstream jasper/backport/10528/5.2
+  git checkout jasper/backport/10528/5.2
+
+Now, just follow one of these two paths:
+
+
+1. GUIDED BACKPORT
+
+You should do the guided backport if you want to apply the backported changes
+while resolving the conflicts on each commit. For most cases, this is what you
+want to do.
+
+The following script will rebase the commits that need to be backported onto
+a new temporary branch. Resolve any conflicts as you normally would during a
+rebase. Do not remove these backport-*.rej files, and feel free to add
+additional commits if that's necessary:
+
+    sh backport-guided-begin.rej
+
+Once the conficts are resolved and the rebase is completed, the following
+script will update the local backport branch with the changes, remove the
+temporary branch that was created, remove the remnants of this backport commit
+and squash the newly resolved commits (and any others you may have added) into
+a single backport commit with the proper commit message:
+
+    sh backport-guided-finish.rej
+
+At this point, you should be on the local backport branch, and it should be
+exactly 1 commit ahead of the intended target. The commit message should be
+very similar if not identical to the PR itself, and the changeset should
+include all of the changes you intended to backport and none of these
+backport-*.rej files.
+
+Now just replace the contents of the pull request with your local changes:
+
+    git push -f upstream jasper/backport/10528/5.2
+
+
+2. ALMOST COMPLETELY MANUAL
+
+You should do this option if there are just so many conflicts that it's easier
+to rebuild the entire changeset from scratch. You'll still work on the local
+backport branch which should be up to date with the intended target.
+
+Feel free to add as many commits as you'd like and don't worry about fancy
+commit messages - we're just going to squash them down and replace the message
+when you're finished.
+
+Once the changes are committed on your local backport branch, the following
+script will remove the remnants of this backport commit and squash the newly
+created commits into a single backport commit with the proper commit message.
+
+    sh backport-wrangle-into-commit.rej
+
+At this point, you should be on the local backport branch, and it should be
+exactly 1 commit ahead of the intended target. The commit message should be
+very similar if not identical to the PR itself, and the changeset should
+include all of the changes you intended to backport and none of these
+backport-*.rej files.
+
+Now just replace the contents of the pull request with your local changes:
+
+    git push -f upstream jasper/backport/10528/5.2

backport-commit-message.rej

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+allowing 0 for extent value
+
+Backports PR #10528
+
+**Commit 1:**
+allowing 0 for extent value
+
+* Original sha: 17f72c9bcb317a986d385340cb49952073296bcf
+* Authored by ppisljar <peter.pisljar@gmail.com> on 2017-02-23T09:23:48Z
+
+**Commit 2:**
+fixing based on review
+
+* Original sha: dbef23a8db3673a1d3b219e1eab4b7a070a00fe4
+* Authored by ppisljar <peter.pisljar@gmail.com> on 2017-02-28T10:15:30Z

backport-guided-begin.rej

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+#!/bin/sh
+
+REMOTE="upstream"
+BRANCH="jasper/backport/10528/5.2"
+WORKING_BRANCH="tmp/$BRANCH"
+STARTING_SHA="17f72c9bcb317a986d385340cb49952073296bcf"
+ENDING_SHA="dbef23a8db3673a1d3b219e1eab4b7a070a00fe4"
+
+git fetch $REMOTE
+
+git checkout -b $WORKING_BRANCH $ENDING_SHA
+git rebase $STARTING_SHA^ --onto $BRANCH

backport-guided-finish.rej

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+BRANCH="jasper/backport/10528/5.2"
+WORKING_BRANCH="tmp/$BRANCH"
+
+git checkout $BRANCH
+git reset --hard $WORKING_BRANCH
+git branch -D $WORKING_BRANCH
+
+sh backport-wrangle-into-commit.rej

backport-wrangle-into-commit.rej

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+REMOTE="upstream"
+BRANCH="jasper/backport/10528/5.2"
+COMMIT_MSG=`cat backport-commit-message.rej`
+
+git reset --soft $REMOTE/$BRANCH
+git stash
+git reset --hard HEAD^
+git stash apply --index
+
+git commit -m "$COMMIT_MSG" --no-verify