enable modification of the execution environment options

src/de/uni_passau/fim/seibt/gitwrapper/repo/GitWrapper.java

@@ -43,7 +43,7 @@ public class GitWrapper extends ToolWrapper {
     private static final String GIT_VERSION_C = "--version";
     private static final String GIT_VERSION_PREFIX = "git version";
 
-    private static final Map<String, String> environment;
+    private static final Map<String, String> defaultEnvironment;
     private static final List<String> defaultOptions;
 
     static {
@@ -53,7 +53,7 @@ public class GitWrapper extends ToolWrapper {
         env.put("LANGUAGE", locale);
         env.put("LC_ALL", locale);
         env.put("LANG", locale);
-        environment = Collections.unmodifiableMap(env);
+        defaultEnvironment = Collections.unmodifiableMap(env);
 
         List<String> defOptions = new ArrayList<>();
 
@@ -347,6 +347,24 @@ public class GitWrapper extends ToolWrapper {
      * @return the result of the execution
      */
     public Optional<ExecRes> exec(File workingDirectory, String firstParameter, String... parameters) {
+        return exec(workingDirectory, null, firstParameter, parameters);
+    }
+
+    /**
+     * Executes '&lt;git command&gt; &lt;firstParameter&gt; &lt;parameters&gt;' and returns the exit code and the output
+     * of the command. If there is an exception executing the command an empty {@link Optional} will be returned.
+     *
+     * @param workingDirectory
+     *         the working directory for the command execution
+     * @param environment
+     *         additional environment variables for the command execution
+     * @param firstParameter
+     *         the first git parameter
+     * @param parameters
+     *         the git parameters
+     * @return the result of the execution
+     */
+    public Optional<ExecRes> exec(File workingDirectory, Map<String, String> environment, String firstParameter, String... parameters) {
         List<String> pars = new ArrayList<>(defaultOptions.size() + ((parameters != null) ? parameters.length + 1 : 1));
 
         pars.addAll(defaultOptions);
@@ -356,6 +374,16 @@ public class GitWrapper extends ToolWrapper {
             Collections.addAll(pars, parameters);
         }
 
-        return exec(workingDirectory, true, environment, pars);
+        Map<String, String> env;
+
+        if (environment != null) {
+            env = new HashMap<>(defaultEnvironment.size() + environment.size());
+            env.putAll(environment);
+            env.putAll(defaultEnvironment);
+        } else {
+            env = GitWrapper.defaultEnvironment;
+        }
+
+        return exec(workingDirectory, true, env, pars);
     }
 }