Workaround for #14873 (#14890) (#14893)

import platform-specific ffi binaries from JRuby 9.3.9.0 to overcome jruby/jruby#7579

Since JRuby ignores the files in "lib/jni" and uses the ones inside "lib/jruby.jar" instead, we have to inject the older versions into the new JRuby's "jruby.jar"

fixes #14873

(cherry picked from commit 281ce70)

Co-authored-by: João Duarte <jsvd@users.noreply.github.com>

rubyUtils.gradle

@@ -189,6 +189,8 @@ def versionsPath = project.hasProperty("LOGSTASH_CORE_PATH") ? LOGSTASH_CORE_PAT
 versionMap = (Map) (new Yaml()).load(new File("${versionsPath}").text)
 
 String jRubyURL
+String previousJRubyVersion = "9.3.9.0"
+String previousJRubyURL = "https://repo1.maven.org/maven2/org/jruby/jruby-dist/${previousJRubyVersion}/jruby-dist-${previousJRubyVersion}-bin.tar.gz"
 String jRubyVersion
 String jRubySha1
 Boolean doChecksum
@@ -204,6 +206,7 @@ if (versionMap["jruby-runtime-override"]) {
     doChecksum = true
 }
 def jrubyTarPath = "${projectDir}/vendor/_/jruby-dist-${jRubyVersion}-bin.tar.gz"
+def previousJrubyTarPath = "${projectDir}/vendor/_/jruby-dist-${previousJRubyVersion}-bin.tar.gz"
 
 def customJRubyDir = project.hasProperty("custom.jruby.path") ? project.property("custom.jruby.path") : ""
 def customJRubyVersion = customJRubyDir == "" ? "" : Files.readAllLines(Paths.get(customJRubyDir, "VERSION")).get(0).trim()
@@ -218,6 +221,15 @@ tasks.register("downloadJRuby", Download) {
     dest new File("${projectDir}/vendor/_", "jruby-dist-${jRubyVersion}-bin.tar.gz")
 }
 
+tasks.register("downloadPreviousJRuby", Download) {
+    description "Download previous JRuby artifact from this specific URL: ${previousJRubyURL}"
+    src previousJRubyURL
+    onlyIfNewer true
+    inputs.file(versionsPath)
+    outputs.file(previousJrubyTarPath)
+    dest new File("${projectDir}/vendor/_", "jruby-dist-${previousJRubyVersion}-bin.tar.gz")
+}
+
 downloadJRuby.onlyIf { customJRubyDir == "" }
 
 tasks.register("verifyFile", Verify) {
@@ -262,9 +274,26 @@ tasks.register("installCustomJRuby", Copy) {
 
 installCustomJRuby.onlyIf { customJRubyDir != "" }
 
+tasks.register("downloadAndInstallPreviousJRubyFFI", Copy) {
+    dependsOn=[downloadPreviousJRuby]
+    description "Install previous JRuby FFI files in the new JRuby directory"
+    inputs.file(previousJrubyTarPath)
+    outputs.dir("${projectDir}/vendor/jruby/tmp")
+    from tarTree(downloadPreviousJRuby.dest)
+    eachFile { f ->
+        f.path = f.path.replaceFirst("^jruby-${previousJRubyVersion}", '')
+    }
+    // Copy only the previous builds of libjffi that changed from JRuby 9.3.9.0 to 9.3.10.0
+    include "**/lib/jni/**/*"
+
+    includeEmptyDirs = false
+    into "${projectDir}/vendor/jruby/tmp"
+}
+
 
 tasks.register("downloadAndInstallJRuby", Copy) {
-    dependsOn=[verifyFile, installCustomJRuby]
+    // TODO remove downloadAndInstallPreviousJRubyFFI after https://github.com/elastic/logstash/issues/14873 is fixed
+    dependsOn=[verifyFile, downloadAndInstallPreviousJRubyFFI, installCustomJRuby]
     description "Install JRuby in the vendor directory"
     inputs.file(jrubyTarPath)
     outputs.dir("${projectDir}/vendor/jruby")
@@ -274,9 +303,18 @@ tasks.register("downloadAndInstallJRuby", Copy) {
     }
     exclude "**/stdlib/rdoc/**"
     exclude "**/did_you_mean-*/evaluation/**" // licensing issue https://github.com/jruby/jruby/issues/6471
+    exclude "**/lib/jni/**/**"
 
     includeEmptyDirs = false
     into "${projectDir}/vendor/jruby"
+
+    doLast {
+        ant.jar(destfile: "${projectDir}/vendor/jruby/lib/jruby.jar", update: true) {
+            fileset(dir: "${projectDir}/vendor/jruby/tmp/lib")
+        }
+        delete files("${projectDir}/vendor/jruby/tmp")
+    }
+
 }
 
 downloadAndInstallJRuby.onlyIf { customJRubyDir == "" }