RFR: 8315074: Possible null pointer access in native glass [v2]

[Jayathirth D V]

> At multiple places in native glass code we don't have appropriate NULL checks which might result in null pointer access.
> 
> Added appropriate checks and all test run is green.

Jayathirth D V has updated the pull request incrementally with one additional commit since the last revision:

  Fix typo

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Changes:
  - all: https://git.openjdk.org/jfx/pull/1223/files
  - new: https://git.openjdk.org/jfx/pull/1223/files/e6175de4..68e3b196

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1223&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1223&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1223.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1223/head:pull/1223

PR: https://git.openjdk.org/jfx/pull/1223