Add options -b and -I to package command

* With -b building a build package can be requested. It will be empty
  save for the .PackageInfo. No license check is performed.
* -I allows to specify an install path.

src/bin/package/command_create.cpp

@@ -34,6 +34,8 @@ command_create(int argc, const char* const* argv)
 {
 	const char* changeToDirectory = NULL;
 	const char* packageInfoFileName = NULL;
+	const char* installPath = NULL;
+	bool isBuildPackage = false;
 	bool quiet = false;
 	bool verbose = false;
 
@@ -46,11 +48,16 @@ command_create(int argc, const char* const* argv)
 		};
 
 		opterr = 0; // don't print errors
-		int c = getopt_long(argc, (char**)argv, "+C:hi:qv", sLongOptions, NULL);
+		int c = getopt_long(argc, (char**)argv, "+bC:hi:I:qv", sLongOptions,
+			NULL);
 		if (c == -1)
 			break;
 
 		switch (c) {
+			case 'b':
+				isBuildPackage = true;
+				break;
+
 			case 'C':
 				changeToDirectory = optarg;
 				break;
@@ -63,6 +70,10 @@ command_create(int argc, const char* const* argv)
 				packageInfoFileName = optarg;
 				break;
 
+			case 'I':
+				installPath = optarg;
+				break;
+
 			case 'q':
 				quiet = true;
 				break;
@@ -83,6 +94,13 @@ command_create(int argc, const char* const* argv)
 
 	const char* packageFileName = argv[optind++];
 
+	// -I is only allowed when -b is given
+	if (installPath != NULL && !isBuildPackage) {
+		fprintf(stderr, "Error: \"-I\" is only allowed when \"-b\" is "
+			"given.\n");
+		return 1;
+	}
+
 	// create package
 	PackageWriterListener listener(verbose, quiet);
 	BPackageWriter packageWriter(&listener);
@@ -97,6 +115,7 @@ command_create(int argc, const char* const* argv)
 		if (packageInfoFD < 0) {
 			fprintf(stderr, "Error: Failed to open package info file \"%s\": "
 				"%s\n", packageInfoFileName, strerror(errno));
+			return 1;
 		}
 	}
 
@@ -106,12 +125,30 @@ command_create(int argc, const char* const* argv)
 			listener.PrintError(
 				"Error: Failed to change the current working directory to "
 				"\"%s\": %s\n", changeToDirectory, strerror(errno));
+			return 1;
+		}
+	}
+
+	if (isBuildPackage)
+		packageWriter.SetCheckLicenses(false);
+
+	// set install path, if specified
+	if (installPath != NULL) {
+		result = packageWriter.SetInstallPath(installPath);
+		if (result != B_OK) {
+			fprintf(stderr, "Error: Failed to set the package install path: "
+				"%s\n", strerror(result));
+			return 1;
 		}
 	}
 
 	// add all files of the current directory, save for the .PackageInfo
-	if (add_current_directory_entries(packageWriter, listener, true) != B_OK)
+	if (!isBuildPackage) {
+		if (add_current_directory_entries(packageWriter, listener, true)
+				!= B_OK) {
 			return 1;
+		}
+	}
 
 	// add the .PackageInfo
 	result = packageWriter.AddEntry(B_HPKG_PACKAGE_INFO_FILE_NAME,

src/bin/package/package.cpp

@@ -41,10 +41,19 @@ static const char* kUsage =
 	"  create [ <options> ] <package>\n"
 	"    Creates package file <package> from contents of current directory.\n"
 	"\n"
+	"    -b         - Create an empty build package. Only the .PackageInfo "
+		"will\n"
+	"                 be added.\n"
 	"    -C <dir>   - Change to directory <dir> before adding entries.\n"
 	"    -i <info>  - Use the package info file <info>. It will be added as\n"
 	"                 \".PackageInfo\", overriding a \".PackageInfo\" file,\n"
 	"                 existing.\n"
+	"    -I <path>  - Set the package's installation path to <path>. This is\n"
+	"                 an option only for use in package building. It will "
+		"cause\n"
+	"                 the package .self link to point to <path>, which is "
+		"useful\n"
+	"                 to redirect a \"make install\". Only allowed with -b.\n"
 	"    -q         - Be quiet (don't show any output except for errors).\n"
 	"    -v         - Be verbose (show more info about created package).\n"
 	"\n"