Fix update common script

Author: amitprakash07

Scripts/UpdateCommon.py

@@ -110,13 +110,12 @@ def UpdateGitHubRepo(repoRootUrl, location, commit):
 
         print("Directory " + targetPath + " does not exist. \n\tUsing 'git clone' to get from " + ghRepoSource)
         sys.stdout.flush()
-        try:
-            subprocess.check_call(["git", "-C", scriptRoot, "clone", ghRepoSource, targetPath, "--branch", reqdCommit], shell=SHELLARG)
-        except subprocess.CalledProcessError as e:
-            print("'git clone' failed with returncode: %d\n" % e.returncode)
+
+        if False == GpaUtils.CloneGitRepo(ghRepoSource, reqdCommit, targetPath):
             sys.exit(1)
-        sys.stderr.flush()
-        sys.stdout.flush()
+
+        if reqdCommit is not None:
+            GpaUtils.SwitchToBranchOrRef(targetPath, reqdCommit)
 
 def ShowRevisions():
     repos_revision_map={}

Scripts/gpa_utils.py

@@ -9,6 +9,13 @@
 import subprocess
 import urllib
 
+SHELLARG = False
+# The environment variable SHELL is only set for Cygwin or Linux
+SHELLTYPE = os.environ.get('SHELL')
+if ( SHELLTYPE == None ):
+    # running on windows under default shell
+    SHELLARG = True
+
 if sys.version_info.major == 3:
     import urllib.request
 
@@ -74,3 +81,34 @@ def Download(source_url, dest_dir, file_name):
     else:
         print("Unable to download file")
         return False
+
+def SwitchToBranchOrRef(localrepopath, branch_or_ref):
+    if os.path.isdir(localrepopath):
+        currentDir = os.getcwd()
+        os.chdir(localrepopath)
+        commandArgs = ["git", "checkout", branch_or_ref]
+        try:
+            sys.stdout.flush()
+            p = subprocess.check_call(commandArgs, shell=SHELLARG)
+            sys.stdout.flush()
+            sys.stderr.flush()
+            os.chdir(currentDir)
+        except subprocess.CalledProcessError as e:
+            print ("'git clone' failed with returncode: %d\n" % e.returncode)
+            os.chdir(currentDir)
+            sys.stderr.flush()
+            sys.exit(1)
+
+def CloneGitRepo(remote, branch, target):
+    target = os.path.normpath(target)
+    commandArgs = ["git", "clone", remote, target]
+    try:
+        sys.stdout.flush()
+        subprocess.check_call(commandArgs, shell=SHELLARG)
+        sys.stdout.flush()
+        sys.stderr.flush()
+        return True
+    except subprocess.CalledProcessError as e:
+        print ("'git clone' failed with returncode: %d\n" % e.returncode)
+        sys.stderr.flush()
+        return False