git: a47b28442179 - main - java/openjdk11(-jre): fix build with clang 12

[Dimitry Andric]

The branch main has been updated by dim (src committer):

URL: https://cgit.FreeBSD.org/ports/commit/?id=a47b2844217978a9b577182214c795dbfe471451

commit a47b2844217978a9b577182214c795dbfe471451
Author:     Dimitry Andric <dim at FreeBSD.org>
AuthorDate: 2021-05-15 14:45:26 +0000
Commit:     Dimitry Andric <dim at FreeBSD.org>
CommitDate: 2021-05-29 14:08:18 +0000

    java/openjdk11(-jre): fix build with clang 12
    
    During an exp-run for llvm 12 (see bug 255570), it turned out that
    java/openjdk11 and java/openjdk11-jre do not build with clang 12.0.0:
    
    Creating interim jimage
    Compiling 2 files for BUILD_DEMO_Notepad
    
    This is due to a missing backport of an upstream commit:
    
    commit c484d8904285652246c3af212a4211b9a8955149
    Author: Thomas Stuefe <stuefe at openjdk.org>
    Date:   Tue Mar 16 05:49:01 2021 +0000
    
        8263557: Possible NULL dereference in Arena::destruct_contents()
    
        Reviewed-by: kbarrett, coleenp
    
    Approved by:    maintainer timeout (2 weeks)
    PR:             255900
    MFH:            2021Q2
---
 java/openjdk11/files/patch-commit-c484d890428 | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/java/openjdk11/files/patch-commit-c484d890428 b/java/openjdk11/files/patch-commit-c484d890428
new file mode 100644
index 000000000000..39ac7a7e8e46
--- /dev/null
+++ b/java/openjdk11/files/patch-commit-c484d890428
@@ -0,0 +1,23 @@
+commit c484d8904285652246c3af212a4211b9a8955149
+Author: Thomas Stuefe <stuefe at openjdk.org>
+Date:   Tue Mar 16 05:49:01 2021 +0000
+
+    8263557: Possible NULL dereference in Arena::destruct_contents()
+    
+    Reviewed-by: kbarrett, coleenp
+
+diff --git src/hotspot/share/memory/arena.cpp src/hotspot/share/memory/arena.cpp
+index 8388f68c359..16059bed9be 100644
+--- src/hotspot/share/memory/arena.cpp
++++ src/hotspot/share/memory/arena.cpp
+@@ -310,7 +310,9 @@ void Arena::destruct_contents() {
+   // reset size before chop to avoid a rare racing condition
+   // that can have total arena memory exceed total chunk memory
+   set_size_in_bytes(0);
+-  _first->chop();
++  if (_first != NULL) {
++    _first->chop();
++  }
+   reset();
+ }
+