chg: [internal] Current branch and commit checking

app/Lib/Tools/GitTool.php

@@ -37,4 +37,38 @@ class GitTool
         }
         return $data[0]['sha'];
     }
+
+    /**
+     * `git rev-parse HEAD`
+     * @return string
+     * @throws Exception
+     */
+    public static function currentCommit()
+    {
+        $head = rtrim(FileAccessTool::readFromFile(ROOT . '/.git/HEAD'));
+        if (substr($head, 0, 5) === 'ref: ') {
+            $path = substr($head, 5);
+            return rtrim(FileAccessTool::readFromFile(ROOT . '/.git/' . $path));
+        }  else if (strlen($head) === 40) {
+            return $head;
+        } else {
+            throw new Exception("Invalid head $head");
+        }
+    }
+
+    /**
+     * `git symbolic-ref HEAD`
+     * @return string
+     * @throws Exception
+     */
+    public static function currentBranch()
+    {
+        $head = rtrim(FileAccessTool::readFromFile(ROOT . '/.git/HEAD'));
+        if (substr($head, 0, 5) === 'ref: ') {
+            $path = substr($head, 5);
+            return str_replace('refs/heads/', '', $path);
+        } else {
+            throw new Exception("ref HEAD is not a symbolic ref");
+        }
+    }
 }

app/Model/AppModel.php

@@ -2764,8 +2764,11 @@ class AppModel extends Model
     {
         static $commit;
         if ($commit === null) {
-            $commit = exec('git rev-parse HEAD');
-            if (!$commit) {
+            App::uses('GitTool', 'Tools');
+            try {
+                $commit = GitTool::currentCommit();
+            } catch (Exception $e) {
+                $this->logException('Could not get current git commit', $e, LOG_NOTICE);
                 $commit = false;
             }
         }

app/Model/Server.php

@@ -3863,11 +3863,11 @@ class Server extends AppModel
 
     public function getCurrentBranch()
     {
-        $ref = exec("git symbolic-ref HEAD");
-        if ($ref) {
-            return str_replace('refs/heads/', '', $ref);
+        try {
+            return GitTool::currentBranch();
+        } catch (Exception $e) {
+            return false;
         }
-        return false;
     }
 
     public function checkoutMain()