Store filesystem timestamp resolution in extra jgit config

This avoids polluting hand-crafted user level config with
auto-configured options which might disturb in environments where
the user level config is replicated between different machines.

Add a jgit config as parent of the system level config. Persist
measured timestamp resolutions always in this jgit config and read it
via the user global config. This has the effect that auto-configured
timestamp resolution will be used by default and can be overridden in
either the system level or user level config.

Store the jgit config under the XDG_CONFIG_HOME directory following the
XDG base directory specification [1] in order to ensure that we have
write permissions to persist the file. This has the effect that each OS
user will use its jgit config since they typically use different
XDG_CONFIG_HOME directories.

If the environment variable XDG_CONFIG_HOME is defined the jgit config
file is located at $XDG_CONFIG_HOME/jgit/config otherwise the default is
~/.config/jgit/config.

If you want to avoid redundant measurement for different OS users
manually copy the values measured and auto-configured for one OS user to
the system level git config.

[1] https://wiki.archlinux.org/index.php/XDG_Base_Directory

Bug: 551850
Change-Id: I0022bd40ae62f82e5b964c2ea25822eb55d94687
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

2 files changed, 33 insertions, 2 deletions

diff --git a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/LocalDiskRepositoryTestCase.java b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/LocalDiskRepositoryTestCase.java
index 5c2cd6ac65..eca8179ece 100644
--- a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/LocalDiskRepositoryTestCase.java
+++ b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/LocalDiskRepositoryTestCase.java
@@ -125,8 +125,9 @@ public abstract class LocalDiskRepositoryTestCase {
 	public void setUp() throws Exception {
 		tmp = File.createTempFile("jgit_test_", "_tmp");
 		CleanupThread.deleteOnShutdown(tmp);
-		if (!tmp.delete() || !tmp.mkdir())
+		if (!tmp.delete() || !tmp.mkdir()) {
 			throw new IOException("Cannot create " + tmp);
+		}
 
 		mockSystemReader = new MockSystemReader();
 		SystemReader.setInstance(mockSystemReader);
@@ -137,7 +138,11 @@ public abstract class LocalDiskRepositoryTestCase {
 		// the same one here
 		FS.getFileStoreAttributes(tmp.toPath().getParent());
 
-		FileBasedConfig userConfig = new FileBasedConfig(
+		FileBasedConfig jgitConfig = new FileBasedConfig(
+				new File(tmp, "jgitconfig"), FS.DETECTED);
+		FileBasedConfig systemConfig = new FileBasedConfig(jgitConfig,
+				new File(tmp, "systemgitconfig"), FS.DETECTED);
+		FileBasedConfig userConfig = new FileBasedConfig(systemConfig,
 				new File(tmp, "usergitconfig"), FS.DETECTED);
 		// We have to set autoDetach to false for tests, because tests expect to be able
 		// to clean up by recursively removing the repository, and background GC might be
@@ -145,7 +150,10 @@ public abstract class LocalDiskRepositoryTestCase {
 		userConfig.setBoolean(ConfigConstants.CONFIG_GC_SECTION,
 				null, ConfigConstants.CONFIG_KEY_AUTODETACH, false);
 		userConfig.save();
+		mockSystemReader.setJGitConfig(jgitConfig);
+		mockSystemReader.setSystemGitConfig(systemConfig);
 		mockSystemReader.setUserGitConfig(userConfig);
+
 		ceilTestDirectories(getCeilings());
 
 		author = new PersonIdent("J. Author", "jauthor@example.com");
diff --git a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/MockSystemReader.java b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/MockSystemReader.java
index 13c2932282..630c8a4799 100644
--- a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/MockSystemReader.java
+++ b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/MockSystemReader.java
@@ -103,6 +103,8 @@ public class MockSystemReader extends SystemReader {
 
 	private FileBasedConfig userGitConfig;
 
+	private FileBasedConfig jgitConfig;
+
 	FileBasedConfig systemGitConfig;
 
 	/**
@@ -119,6 +121,16 @@ public class MockSystemReader extends SystemReader {
 	}
 
 	/**
+	 * Set the jgit config stored at $XDG_CONFIG_HOME/jgit/config
+	 *
+	 * @param jgitConfig
+	 *            set the jgit configuration
+	 */
+	public void setJGitConfig(FileBasedConfig jgitConfig) {
+		this.jgitConfig = jgitConfig;
+	}
+
+	/**
 	 * Set the system-level git config
 	 *
 	 * @param systemGitConfig
@@ -142,6 +154,7 @@ public class MockSystemReader extends SystemReader {
 		init(Constants.GIT_COMMITTER_EMAIL_KEY);
 		setProperty(Constants.OS_USER_DIR, ".");
 		userGitConfig = new MockConfig(null, null);
+		jgitConfig = new MockConfig(null, null);
 		systemGitConfig = new MockConfig(null, null);
 		setCurrentPlatform();
 	}
@@ -200,6 +213,11 @@ public class MockSystemReader extends SystemReader {
 	}
 
 	@Override
+	public FileBasedConfig getJGitConfig() {
+		return jgitConfig;
+	}
+
+	@Override
 	public StoredConfig getSystemConfig()
 			throws IOException, ConfigInvalidException {
 		return systemGitConfig;
@@ -333,4 +351,9 @@ public class MockSystemReader extends SystemReader {
 		return "MockSystemReader";
 	}
 
+	@Override
+	public FileBasedConfig openJGitConfig(Config parent, FS fs) {
+		return jgitConfig;
+	}
+
 }