Windows doesn't like "patch"

Signed-off-by: Federico Fissore <f.fissore@arduino.cc>

Author: Federico Fissore

README.md

@@ -63,6 +63,7 @@ Once done, run the following commands:
 go get github.com/go-errors/errors
 go get github.com/stretchr/testify
 go get github.com/jstemmer/go-junit-report
+go get golang.org/x/codereview/patch
 go build
 ```
 

src/arduino.cc/builder/test/downloaded_stuff_patches/avr_platform_patch.patch

@@ -1,6 +1,8 @@
---- downloaded_hardware/arduino/avr/platform.txt	2015-09-10 17:14:15.137942087 +0200
-+++ downloaded_hardware/arduino/avr/platform.txt	2015-09-23 10:27:19.522085331 +0200
-@@ -77,6 +77,12 @@
+diff --git a/downloaded_hardware/arduino/avr/platform.txt b/downloaded_hardware/arduino/avr/platform.txt
+index 537fcc5..4e526d9 100644
+--- a/downloaded_hardware/arduino/avr/platform.txt
++++ b/downloaded_hardware/arduino/avr/platform.txt
+@@ -81,6 +81,12 @@ recipe.size.regex=^(?:\.text|\.data|\.bootloader)\s+([0-9]+).*
  recipe.size.regex.data=^(?:\.data|\.bss|\.noinit)\s+([0-9]+).*
  recipe.size.regex.eeprom=^(?:\.eeprom)\s+([0-9]+).*
 

src/arduino.cc/builder/test/downloaded_stuff_patches/hid_library_properties.patch.disabled

@@ -37,6 +37,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"github.com/go-errors/errors"
+	"golang.org/x/codereview/patch"
 	"io"
 	"io/ioutil"
 	"net/http"
@@ -133,20 +134,24 @@ func DownloadCoresAndToolsAndLibraries(t *testing.T) {
 
 	download(t, cores, boardsManagerCores, boardsManagerRedBearCores, tools, boardsManagerTools, boardsManagerRFduinoTools, libraries)
 
-	patch(t)
+	patchFiles(t)
 }
 
 // FIXME: once patched cores are released, patching them will be unnecessary
-func patch(t *testing.T) {
+func patchFiles(t *testing.T) {
 	files, err := ioutil.ReadDir(PATCHES_FOLDER)
 	NoError(t, err)
 
 	for _, file := range files {
 		if filepath.Ext(file.Name()) == ".patch" {
-			cmd := exec.Command("patch", "-N", "-p0", "-r", "-", "-i", filepath.Join(PATCHES_FOLDER, file.Name()))
-			cmd.CombinedOutput()
-			//output, _ := cmd.CombinedOutput()
-			//fmt.Println(string(output))
+			data, err := ioutil.ReadFile(Abs(t, filepath.Join(PATCHES_FOLDER, file.Name())))
+			NoError(t, err)
+			patchSet, err := patch.Parse(data)
+			NoError(t, err)
+			operations, err := patchSet.Apply(ioutil.ReadFile)
+			for _, op := range operations {
+				ioutil.WriteFile(op.Dst, op.Data, os.FileMode(0644))
+			}
 		}
 	}
 }