From 873ec1d4e81a567152ed688d30faa46185112767 Mon Sep 17 00:00:00 2001
From: Gregor Schmidt <schmidt@nach-vorne.eu>
Date: Wed, 1 Jun 2016 11:41:08 +0200
Subject: [PATCH] Replace ImageMagick shellouts with fastimage_resize

Adds optional dependency to GD lib. Removes dependency to mimemagic, since there is no immediate need for it anymore.

To install GD lib use one of the following commands:

Mac OS: brew install gd
Debian: apt-get install libgd3-dev
Ubuntu: apt-get install libgd2-noxpm-dev
---
 Gemfile                  | 10 +++++++--
 app/models/attachment.rb |  2 +-
 lib/redmine/thumbnail.rb | 56 +++++++++++++++++++++++++++---------------------
 3 files changed, 41 insertions(+), 27 deletions(-)

diff --git a/Gemfile b/Gemfile
index f359e55..c43f769 100644
--- a/Gemfile
+++ b/Gemfile
@@ -14,12 +14,18 @@ gem "protected_attributes"
 gem "actionpack-action_caching"
 gem "actionpack-xml_parser"
 gem "roadie-rails"
-gem "mimemagic"
+
+# Optional gems to create attachment thumbnails
+platforms :mri do
+  group :thumbnails do
+    gem "local-fastimage_resize", "~> 3.1", require: "fastimage/resize"
+  end
+end
 
 # Request at least nokogiri 1.6.7.2 because of security advisories
 gem "nokogiri", ">= 1.6.7.2"
 
-# Request at least rails-html-sanitizer 1.0.3 because of security advisories 
+# Request at least rails-html-sanitizer 1.0.3 because of security advisories
 gem "rails-html-sanitizer", ">= 1.0.3"
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
diff --git a/app/models/attachment.rb b/app/models/attachment.rb
index 4bc674f..734d3fa 100644
--- a/app/models/attachment.rb
+++ b/app/models/attachment.rb
@@ -194,7 +194,7 @@ class Attachment < ActiveRecord::Base
   end
 
   def image?
-    !!(self.filename =~ /\.(bmp|gif|jpg|jpe|jpeg|png)$/i)
+    !!(self.filename =~ /\.(gif|jpg|jpe|jpeg|png)$/i)
   end
 
   def thumbnailable?
diff --git a/lib/redmine/thumbnail.rb b/lib/redmine/thumbnail.rb
index 9321c7b..feb04d2 100644
--- a/lib/redmine/thumbnail.rb
+++ b/lib/redmine/thumbnail.rb
@@ -16,41 +16,49 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 require 'fileutils'
-require 'mimemagic'
+
+begin
+  require 'fastimage/resize' unless defined? FastImage
+rescue LoadError
+  # :thumbnails group not available
+end
 
 module Redmine
   module Thumbnail
-    extend Redmine::Utils::Shell
-
-    CONVERT_BIN = (Redmine::Configuration['imagemagick_convert_command'] || 'convert').freeze
-
     # Generates a thumbnail for the source image to target
     def self.generate(source, target, size)
+
+      # Nothing we can do without the libraries
       return nil unless convert_available?
-      unless File.exists?(target)
-        # Make sure we only invoke Imagemagick if this is actually an image
-        unless File.open(source) {|f| MimeMagic.by_magic(f).try(:image?)}
-          return nil
-        end
-        directory = File.dirname(target)
-        unless File.exists?(directory)
-          FileUtils.mkdir_p directory
-        end
-        size_option = "#{size}x#{size}>"
-        cmd = "#{shell_quote CONVERT_BIN} #{shell_quote source} -thumbnail #{shell_quote size_option} #{shell_quote target}"
-        unless system(cmd)
-          logger.error("Creating thumbnail failed (#{$?}):\nCommand: #{cmd}")
-          return nil
-        end
+
+      # Nothing to do, thumb was already created
+      return target if File.exists?(target)
+
+      fastimage = FastImage.new(source)
+
+      # Cannot read dimensions for source - it's probably not an image
+      return nil if fastimage.size.nil?
+
+      directory = File.dirname(target)
+      FileUtils.mkdir_p(directory) unless File.exists?(directory)
+
+      if fastimage.size.max <= size
+        FileUtils.cp(source, target)
+      elsif fastimage.size.first > fastimage.size.last
+        fastimage.resize(size, 0, :outfile => target, :jpeg_quality => 90)
+      else
+        fastimage.resize(0, size, :outfile => target, :jpeg_quality => 90)
       end
+
       target
+
+    rescue FastImage::FastImageException
+      logger.error("Creating thumbnail failed - #{$!.class.name}: #{$!.message}")
+      nil
     end
 
     def self.convert_available?
-      return @convert_available if defined?(@convert_available)
-      @convert_available = system("#{shell_quote CONVERT_BIN} -version") rescue false
-      logger.warn("Imagemagick's convert binary (#{CONVERT_BIN}) not available") unless @convert_available
-      @convert_available
+      !!defined?(FastImage)
     end
 
     def self.logger
-- 
2.8.0