Add support for pre-uninstall scripts

This is analoguous to post-install scripts.

Defines a new recipe attribute PRE_UNINSTALL_SCRIPTS and new directory
variables $preUninstallDir and $relativePreUninstallDir.

Fixes haikuports#306.

HaikuPorter/Package.py

@@ -400,6 +400,9 @@ def _generatePackageInfo(self, packageInfoPath, requiresToUse, quiet,
 				self._writePackageInfoListQuotePaths(infoFile,
 					self.recipeKeys['POST_INSTALL_SCRIPTS'],
 					'post-install-scripts')
+				self._writePackageInfoListQuotePaths(infoFile,
+					self.recipeKeys['PRE_UNINSTALL_SCRIPTS'],
+					'pre-uninstall-scripts')
 
 			# Generate SourceURL lines for all ports, regardless of license.
 			# Re-use the download URLs, as specified in the recipe.

HaikuPorter/Policy.py

@@ -82,7 +82,8 @@ def checkPackage(self, package, packageFile):
 		self._checkMisplacedDevelopLibraries()
 		self._checkGlobalWritableFiles()
 		self._checkUserSettingsFiles()
-		self._checkPostInstallScripts()
+		self._checkPostInstallAndPreUninstallScripts('POST_INSTALL_SCRIPTS', 'post-install')
+		self._checkPostInstallAndPreUninstallScripts('PRE_UNINSTALL_SCRIPTS', 'pre-uninstall')
 
 		if self.strict and self.violationEncountered:
 			sysExit("packaging policy violation(s) in strict mode")
@@ -465,10 +466,10 @@ def _checkUserSettingsFiles(self):
 						'"%s" for user settings file "%s" as included'
 						% (components[2], components[0]))
 
-	def _checkPostInstallScripts(self):
+	def _checkPostInstallAndPreUninstallScripts(self, recipeKey, scriptType):
 		# check whether declared scripts exist
 		declaredFiles = set()
-		for script in self.package.recipeKeys['POST_INSTALL_SCRIPTS']:
+		for script in self.package.recipeKeys[recipeKey]:
 			if script.lstrip().startswith('#'):
 				continue
 
@@ -480,18 +481,18 @@ def _checkPostInstallScripts(self):
 
 			absScript = os.path.join(self.package.packagingDir, script)
 			if not os.path.exists(absScript):
-				self._violation('Package declares non-existent post-install '
-					'script "%s"' % script)
+				self._violation('Package declares non-existent %s '
+					'script "%s"' % (scriptType, script))
 
 		# check whether existing scripts are declared
-		postInstallDir = 'boot/post-install'
-		dir = os.path.join(self.package.packagingDir, postInstallDir)
+		relativeDir = 'boot/' + scriptType
+		dir = os.path.join(self.package.packagingDir, relativeDir)
 		if os.path.exists(dir):
 			for script in os.listdir(dir):
-				path = postInstallDir + '/' + script
+				path = relativeDir + '/' + script
 				if path not in declaredFiles:
-					self._violation('script "%s" not declared as post-install '
-						'script' % path)
+					self._violation('script "%s" not declared as %s '
+						'script' % (path, scriptType))
 
 	def _violation(self, message):
 		self.violationEncountered = True

HaikuPorter/Port.py

@@ -1212,6 +1212,7 @@ def _updateShellVariables(self, forParsing):
 			'documentationDir': 'documentation',
 			'fontsDir': 'data/fonts',
 			'postInstallDir': 'boot/post-install',
+			'preUninstallDir': 'boot/pre-uninstall',
 			'preferencesDir': 'preferences',
 			'settingsDir': 'settings',
 		}

HaikuPorter/RecipeAttributes.py

@@ -205,6 +205,13 @@ def getRecipeFormatVersion():
 		'extendable': Extendable.DEFAULT,
 		'indexable': False,
 	},
+	'PRE_UNINSTALL_SCRIPTS': {
+		'type': list,
+		'required': False,
+		'default': [],
+		'extendable': Extendable.DEFAULT,
+		'indexable': False,
+	},
 	'PROVIDES': {
 		'type': ProvidesList,
 		'required': True,