package: prevent creating a package that contains itself.

Fixes #10117.

Change-Id: I4be59189a47dd0ad400fe46786d7058be4ed6d3f
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2778
Reviewed-by: waddlesplash <[email protected]>

src/bin/package/command_create.cpp

@@ -14,6 +14,7 @@
 #include <unistd.h>
 
 #include <Entry.h>
+#include <Path.h>
 
 #include <package/PackageInfo.h>
 #include <package/hpkg/HPKGDefs.h>
@@ -120,6 +121,18 @@ command_create(int argc, const char* const* argv)
 		return 1;
 	}
 
+	BPath outputPath(packageFileName, NULL, true);
+	BPath inputPath(changeToDirectory, NULL, true);
+	BPath parent;
+	while (outputPath.GetParent(&parent) == B_OK) {
+		if (outputPath == inputPath) {
+			fprintf(stderr, "Error: output package can't be in the same "
+				"directory as input files.");
+			return 1;
+		}
+		outputPath = parent;
+	}
+
 	// create package
 	BPackageWriterParameters writerParameters;
 	writerParameters.SetCompressionLevel(compressionLevel);