use .IsSet() instead if .Get() != NULL

Change-Id: Ia2b7a719fd398e78cc3b11d4f7b02cb81179f65f
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3488
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

Merge branch 'master' into package-management

Additional changes:
* Add src/system/kernel/lib/zlib, which builds a kernel version of zlib,
needed by packagefs.
* BuildFeatures: Add a build feature

Merge branch 'master' into package-management

Additional changes:
* Add src/system/kernel/lib/zlib, which builds a kernel version of zlib,
needed by packagefs.
* BuildFeatures: Add a build feature "gcc2" to allow for easier checks.
* Referenceable.cpp: Include <OS.h> instead of <debugger.h>. The latter
is not needed and prevents building for the build platform.
* zlib/zutil.h: Fix gcc 2 build. We really should use the external
package instead.

Conflicts:
.gitignore
build/jam/BuildSetup
build/jam/FileRules
build/jam/FloppyBootImage
build/jam/HaikuImage
build/jam/ImageRules
build/jam/KernelRules
build/jam/NetBootArchive
build/jam/OptionalBuildFeatures
build/jam/OptionalLibPackages
build/jam/OptionalPackageDependencies
build/jam/OptionalPackages
build/scripts/build_haiku_image
configure
data/bin/installoptionalpackage
data/system/boot/Bootscript
headers/os/app/Message.h
headers/os/package/PackageInfo.h
headers/os/package/PackageInfoAttributes.h
headers/os/package/PackageInfoSet.h
headers/os/package/PackageRoster.h
headers/os/package/PackageVersion.h
headers/os/package/hpkg/PackageInfoAttributeValue.h
headers/os/storage/FindDirectory.h
headers/os/storage/Node.h
headers/os/support/StringList.h
headers/private/system/directories.h
src/add-ons/kernel/drivers/audio/ac97/es1370/Jamfile
src/add-ons/kernel/file_systems/packagefs/AttributeIndex.cpp
src/add-ons/kernel/file_systems/packagefs/Jamfile
src/add-ons/kernel/file_systems/packagefs/Package.cpp
src/add-ons/kernel/file_systems/packagefs/Package.h
src/add-ons/kernel/file_systems/packagefs/PackageDomain.cpp
src/add-ons/kernel/file_systems/packagefs/PackageDomain.h
src/add-ons/kernel/file_systems/packagefs/PackageFSRoot.cpp
src/add-ons/kernel/file_systems/packagefs/PackageLinkDirectory.cpp
src/add-ons/kernel/file_systems/packagefs/PackageLinkDirectory.h
src/add-ons/kernel/file_systems/packagefs/PackageLinkSymlink.cpp
src/add-ons/kernel/file_systems/packagefs/PackageLinkSymlink.h
src/add-ons/kernel/file_systems/packagefs/PackageLinksDirectory.cpp
src/add-ons/kernel/file_systems/packagefs/PackageNode.h
src/add-ons/kernel/file_systems/packagefs/ResolvableFamily.cpp
src/add-ons/kernel/file_systems/packagefs/Version.cpp
src/add-ons/kernel/file_systems/packagefs/Version.h
src/add-ons/kernel/file_systems/packagefs/Volume.cpp
src/add-ons/kernel/file_systems/packagefs/Volume.h
src/add-ons/kernel/file_systems/packagefs/kernel_interface.cpp
src/add-ons/kernel/file_systems/userlandfs/shared/driver_settings.c
src/apps/deskbar/BarApp.cpp
src/apps/deskbar/BarMenuBar.cpp
src/apps/deskbar/BarMenuBar.h
src/apps/deskbar/BarView.cpp
src/apps/deskbar/BarView.h
src/apps/deskbar/BarWindow.cpp
src/apps/deskbar/BarWindow.h
src/apps/deskbar/DeskbarMenu.cpp
src/apps/deskbar/DeskbarMenu.h
src/apps/deskbar/DeskbarUtils.cpp
src/apps/deskbar/DeskbarUtils.h
src/apps/deskbar/ExpandoMenuBar.cpp
src/apps/deskbar/ExpandoMenuBar.h
src/apps/deskbar/TeamMenu.cpp
src/apps/processcontroller/ProcessController.cpp
src/apps/remotedesktop/RemoteDesktop.cpp
src/bin/bash/config-top.h
src/bin/finddir.c
src/bin/package/Jamfile
src/bin/package/command_add.cpp
src/bin/package/command_create.cpp
src/bin/package/command_list.cpp
src/bin/package_repo/command_list.cpp
src/bin/pkgman/command_refresh.cpp
src/build/libbe/support/Jamfile
src/build/libpackage/Jamfile
src/build/libroot/Jamfile
src/build/libroot/fs.cpp
src/build/libroot/remapped_functions.h
src/kits/locale/MutableLocaleRoster.cpp
src/kits/opengl/GLRendererRoster.cpp
src/kits/package/PackageInfo.cpp
src/kits/package/PackageInfoSet.cpp
src/kits/package/PackageRoster.cpp
src/kits/package/PackageVersion.cpp
src/kits/package/RepositoryCache.cpp
src/kits/package/hpkg/PackageWriterImpl.cpp
src/kits/package/hpkg/ReaderImplBase.cpp
src/kits/package/hpkg/WriterImplBase.cpp
src/kits/print/PrintTransport.cpp
src/kits/print/Printer.cpp
src/kits/screensaver/ScreenSaverRunner.cpp
src/kits/support/StringList.cpp
src/kits/tracker/ContainerWindow.cpp
src/kits/tracker/DeskWindow.cpp
src/kits/tracker/PoseView.cpp
src/libs/print/libprint/Transport.cpp
src/preferences/printers/AddPrinterDialog.cpp
src/preferences/screensaver/ScreenSaverWindow.cpp
src/servers/debug/DebugServer.cpp
src/servers/input/AddOnManager.cpp
src/servers/media_addon/MediaAddonServer.cpp
src/system/boot/Jamfile
src/system/boot/loader/Jamfile
src/system/boot/loader/loader.cpp
src/system/boot/loader/vfs.cpp
src/system/kernel/fs/vfs.cpp
src/system/kernel/fs/vfs_boot.cpp
src/system/libroot/os/find_directory.cpp
src/system/runtime_loader/runtime_loader.cpp
src/tools/package/Jamfile

show more ...

Merge branch 'master' into x86_64

Conflicts:
build/jam/FloppyBootImage
build/jam/OptionalBuildFeatures
build/jam/OptionalPackages
headers/private/shared/cpu_type.h
src/bin/ps.c
src/bin/sysinfo

Merge branch 'master' into x86_64

Conflicts:
build/jam/FloppyBootImage
build/jam/OptionalBuildFeatures
build/jam/OptionalPackages
headers/private/shared/cpu_type.h
src/bin/ps.c
src/bin/sysinfo.cpp
src/kits/tracker/PoseView.cpp
src/preferences/appearance/DecorSettingsView.cpp
src/preferences/virtualmemory/Settings.cpp
src/servers/input/AddOnManager.cpp
src/servers/input/InputServer.cpp
src/servers/input/InputServerMethod.cpp
src/system/boot/Jamfile
src/system/boot/platform/raspberrypi_arm/mmu.cpp
src/system/boot/platform/u-boot/arch/arm/Jamfile
src/system/kernel/arch/x86/arch_cpu.cpp
src/system/kernel/arch/x86/arch_thread.cpp
src/system/kernel/cache/block_cache.cpp
src/system/kernel/vm/VMAnonymousCache.cpp

show more ...

Merge branch 'master' into sam460ex

Add a list of constraints which can be associated with a BALMLayout.

- Add Get{X,Y}Tabs methods.
- Remove SaveLayout and RestoreLayout. These can be implemented outside of BALMLayout.

in BALMLayout::DefaultPolicy, call printf instead of debugger.

This is more user friendly, debugger() was a bit drastic.

Archive more details about areas in BALMLayout.

Make SharedSolver BArchivable to save extra user constraints.

Make BALMLayout::BadLayoutPolicy archivable.

Add initial support for archiving a BALMLayout.

What's supported:
* basic archive/instantiate
* friend layouts
coming soon:
* saving of custom restraints
* archiving of BadLayoutPolicy

Use const overloading on BALMLayout::{X|Y}TabAt().

Add IndexOf methods.

Allow left and top tab to be NULL.

Replace BALMLayout::Ordered*Tabs() method with *TabAt(int, bool sorted).

Make BALMLayout::BasePreferredSize() useful again.

Pass more information to BadLayoutPolicy.

Also, re-add BadLayoutPolicy invocations, which were lost while creating
SharedSolver.

Improve efficiency when validating an ALM layout.

Introduce SharedSolver class to improve BALMLayout's friend feature.

Refactor BALMLayout::AddItem to reduce repitition.

When adding tabs to a BALMLayout, ensure they are fully added.

Let BALM::{X|Y}Tabs be in multiple BALMLayouts, if they are friendly.

Use BReferenceable properties of LinearSpec in BALMLayout.

This saves us from a potential use-afte-free bug.

Make BALMLayout respect its position when nested.

Add the ability to handle bad layouts to BALMLayout.

Compose spacing given to BALMLayout constructor.