From bbb269674270b145614780dbaa2258f6c770ff65 Mon Sep 17 00:00:00 2001
From: Bo Anderson <mail@boanderson.me>
Date: Wed, 10 Jun 2020 16:10:33 +0100
Subject: [PATCH 1/2] language/java: add support for OpenJDK formula

---
 .../Homebrew/extend/os/mac/language/java.rb   | 12 ++++++++--
 Library/Homebrew/language/java.rb             | 24 +++++++++++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/Library/Homebrew/extend/os/mac/language/java.rb b/Library/Homebrew/extend/os/mac/language/java.rb
index b552027a9a..4661652c0b 100644
--- a/Library/Homebrew/extend/os/mac/language/java.rb
+++ b/Library/Homebrew/extend/os/mac/language/java.rb
@@ -4,17 +4,25 @@ module Language
   module Java
     def self.system_java_home_cmd(version = nil)
       version_flag = " --version #{version}" if version
-      "/usr/libexec/java_home#{version_flag}"
+      "/usr/libexec/java_home#{version_flag} --failfast 2>/dev/null"
     end
     private_class_method :system_java_home_cmd
 
     def self.java_home(version = nil)
+      f = find_openjdk_formula(version)
+      return f.opt_libexec/"openjdk.jdk/Contents/Home" if f
+
       cmd = system_java_home_cmd(version)
-      Pathname.new Utils.popen_read(cmd).chomp
+      path = Utils.popen_read(cmd).chomp
+
+      Pathname.new path if path.present?
     end
 
     # @private
     def self.java_home_shell(version = nil)
+      f = find_openjdk_formula(version)
+      return (f.opt_libexec/"openjdk.jdk/Contents/Home").to_s if f
+
       "$(#{system_java_home_cmd(version)})"
     end
   end
diff --git a/Library/Homebrew/language/java.rb b/Library/Homebrew/language/java.rb
index 612ab32c8d..610c73a5b5 100644
--- a/Library/Homebrew/language/java.rb
+++ b/Library/Homebrew/language/java.rb
@@ -2,7 +2,31 @@
 
 module Language
   module Java
+    def self.find_openjdk_formula(version = nil)
+      can_be_newer = version&.end_with?("+")
+      version = version.to_i
+
+      openjdk = Formula["openjdk"]
+      [openjdk, *openjdk.versioned_formulae].find do |f|
+        next false unless f.any_version_installed?
+
+        unless version.zero?
+          major = f.version.to_s[/\d+/].to_i
+          next false if major < version
+          next false if major > version && !can_be_newer
+        end
+
+        true
+      end
+    rescue FormulaUnavailableError
+      nil
+    end
+    private_class_method :find_openjdk_formula
+
     def self.java_home(version = nil)
+      f = find_openjdk_formula(version)
+      return f.opt_libexec if f
+
       req = JavaRequirement.new [*version]
       raise UnsatisfiedRequirements, req.message unless req.satisfied?
 

From 07547e8cae3d28fc7eefbf5ec9d2865a6daff3fd Mon Sep 17 00:00:00 2001
From: Bo Anderson <mail@boanderson.me>
Date: Wed, 10 Jun 2020 16:11:04 +0100
Subject: [PATCH 2/2] extend/pathname: use Java.overridable_java_home_env in
 write_jar_script

---
 Library/Homebrew/compat/language/java.rb        | 3 ++-
 Library/Homebrew/extend/os/mac/language/java.rb | 2 +-
 Library/Homebrew/extend/pathname.rb             | 8 ++------
 Library/Homebrew/language/java.rb               | 2 +-
 4 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/Library/Homebrew/compat/language/java.rb b/Library/Homebrew/compat/language/java.rb
index 3ad89ebc74..2bcf485e2f 100644
--- a/Library/Homebrew/compat/language/java.rb
+++ b/Library/Homebrew/compat/language/java.rb
@@ -5,7 +5,8 @@ module Language
     class << self
       module Compat
         def java_home_cmd(version = nil)
-          odeprecated "Language::Java::java_home_cmd", "Language::Java::java_home"
+          odeprecated "Language::Java.java_home_cmd",
+                      "Language::Java.java_home or Language::Java.overridable_java_home_env"
 
           # macOS provides /usr/libexec/java_home, but Linux does not.
           return system_java_home_cmd(version) if OS.mac?
diff --git a/Library/Homebrew/extend/os/mac/language/java.rb b/Library/Homebrew/extend/os/mac/language/java.rb
index 4661652c0b..a92b386ece 100644
--- a/Library/Homebrew/extend/os/mac/language/java.rb
+++ b/Library/Homebrew/extend/os/mac/language/java.rb
@@ -18,12 +18,12 @@ module Language
       Pathname.new path if path.present?
     end
 
-    # @private
     def self.java_home_shell(version = nil)
       f = find_openjdk_formula(version)
       return (f.opt_libexec/"openjdk.jdk/Contents/Home").to_s if f
 
       "$(#{system_java_home_cmd(version)})"
     end
+    private_class_method :java_home_shell
   end
 end
diff --git a/Library/Homebrew/extend/pathname.rb b/Library/Homebrew/extend/pathname.rb
index e0c331f4dd..c5b9760659 100644
--- a/Library/Homebrew/extend/pathname.rb
+++ b/Library/Homebrew/extend/pathname.rb
@@ -370,12 +370,8 @@ class Pathname
 
   # Writes an exec script that invokes a Java jar
   def write_jar_script(target_jar, script_name, java_opts = "", java_version: nil)
-    mkpath
-    java_home = ("JAVA_HOME=\"#{Language::Java.java_home_shell(java_version)}\" " if java_version)
-    join(script_name).write <<~SH
-      #!/bin/bash
-      #{java_home}exec java #{java_opts} -jar #{target_jar} "$@"
-    SH
+    (self/script_name).write_env_script "java #{java_opts} -jar #{target_jar}",
+                                        Language::Java.overridable_java_home_env(java_version)
   end
 
   def install_metafiles(from = Pathname.pwd)
diff --git a/Library/Homebrew/language/java.rb b/Library/Homebrew/language/java.rb
index 610c73a5b5..77bddccf5f 100644
--- a/Library/Homebrew/language/java.rb
+++ b/Library/Homebrew/language/java.rb
@@ -33,10 +33,10 @@ module Language
       req.java_home
     end
 
-    # @private
     def self.java_home_shell(version = nil)
       java_home(version).to_s
     end
+    private_class_method :java_home_shell
 
     def self.java_home_env(version = nil)
       { JAVA_HOME: java_home_shell(version) }