package kit: Add pre-uninstall scripts feature.

Just like post-install scripts which run shortly after a package is
installed, pre-uninstall scripts are run just before a package is
removed.  Implements enhancement #13427

* Fix script exit code handling vs script launch errors.
* Bump package and repo file version numbers due to new attribute,
  unfortunately makes new .hpkg files not backwards compatible.
* Add pre-uninstall functionality, mostly cloning the post-install
  except in a few places.
* Discover that _RunQueuedScripts() is never called, a future TODO:?
* Update package documentation for pre-uninstall scripts, and use of
  the boot/post-install directory.

Change-Id: I45596255ce74bc102f6e5b606cbf83e4e4347a17
Reviewed-on: https://review.haiku-os.org/c/haiku/+/1504
Reviewed-by: Alexander G. M. Smith <[email protected]>
Reviewed-by: Adrien Destugues <[email protected]>

headers/os/package/CommitTransactionResult.h

@@ -59,6 +59,9 @@ public:
 				B_POST_INSTALL_SCRIPT_NOT_FOUND,
 				B_STARTING_POST_INSTALL_SCRIPT_FAILED,
 				B_POST_INSTALL_SCRIPT_FAILED,
+				B_PRE_UNINSTALL_SCRIPT_NOT_FOUND,
+				B_STARTING_PRE_UNINSTALL_SCRIPT_FAILED,
+				B_PRE_UNINSTALL_SCRIPT_FAILED,
 			};
 
 public:

headers/os/package/PackageInfo.h

@@ -96,6 +96,7 @@ public:
 			const BStringList&	Groups() const;
 
 			const BStringList&	PostInstallScripts() const;
+			const BStringList&	PreUninstallScripts() const;
 
 			const BObjectList<BPackageResolvable>&	ProvidesList() const;
 			const BObjectList<BPackageResolvableExpression>&
@@ -159,6 +160,9 @@ public:
 			void				ClearPostInstallScripts();
 			status_t			AddPostInstallScript(const BString& path);
 
+			void				ClearPreUninstallScripts();
+			status_t			AddPreUninstallScript(const BString& path);
+
 			void				ClearProvidesList();
 			status_t			AddProvides(const BPackageResolvable& provides);
 
@@ -297,6 +301,7 @@ private:
 			BStringList			fGroups;
 
 			BStringList			fPostInstallScripts;
+			BStringList			fPreUninstallScripts;
 
 			ResolvableList		fProvidesList;
 

headers/os/package/PackageInfoAttributes.h

@@ -51,6 +51,8 @@ enum BPackageInfoAttributeID {
 								// list of (Unix) groups defined/needed
 	B_PACKAGE_INFO_POST_INSTALL_SCRIPTS,
 								// list of scripts to be executed post-install
+	B_PACKAGE_INFO_PRE_UNINSTALL_SCRIPTS,
+								// list of scripts to be run before uninstalling
 	//
 	B_PACKAGE_INFO_ENUM_COUNT,
 };

headers/os/package/hpkg/HPKGDefs.h

@@ -18,11 +18,11 @@ namespace BHPKG {
 enum {
 	B_HPKG_MAGIC				= 'hpkg',
 	B_HPKG_VERSION				= 2,
-	B_HPKG_MINOR_VERSION		= 0,
+	B_HPKG_MINOR_VERSION		= 1,
 	//
 	B_HPKG_REPO_MAGIC			= 'hpkr',
 	B_HPKG_REPO_VERSION			= 2,
-	B_HPKG_REPO_MINOR_VERSION	= 0
+	B_HPKG_REPO_MINOR_VERSION	= 1
 };
 
 

headers/os/package/hpkg/PackageAttributes.h

@@ -82,3 +82,10 @@ B_DEFINE_HPKG_ATTRIBUTE(52, STRING,	"package:post-install-script",
 B_DEFINE_HPKG_ATTRIBUTE(53, UINT,	"package:is-writable-directory",
 	PACKAGE_IS_WRITABLE_DIRECTORY)
 B_DEFINE_HPKG_ATTRIBUTE(54, STRING,	"package",				PACKAGE)
+B_DEFINE_HPKG_ATTRIBUTE(55, STRING,	"package:pre-uninstall-script",
+	PACKAGE_PRE_UNINSTALL_SCRIPT)
+// Note: add new entries at the end to avoid breaking index numbers, which are
+// in previously built .hpkg files the build process downloads from elsewhere.
+// Also remember to bump B_HPKG_MINOR_VERSION and B_HPKG_REPO_MINOR_VERSION.
+// And yes, the build (on Haiku) runs packaging tools compiled using your code,
+// which makes it extra fun to debug :-)