Split discoverGitPrefix() code out into discoverGitExe()

Change-Id: I700540eec06efb24eeb09bfcb40420820c32d156
Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/api/AddCommandTest.java

@@ -624,7 +624,7 @@ public class AddCommandTest extends RepositoryTestCase {
 				return this;
 			}
 
-			protected File discoverGitPrefix() {
+			protected File discoverGitExe() {
 				return null;
 			}
 
@@ -669,7 +669,7 @@ public class AddCommandTest extends RepositoryTestCase {
 				return this;
 			}
 
-			protected File discoverGitPrefix() {
+			protected File discoverGitExe() {
 				return null;
 			}
 

org.eclipse.jgit.test/tst/org/eclipse/jgit/api/CommitCommandTest.java

@@ -108,7 +108,7 @@ public class CommitCommandTest extends RepositoryTestCase {
 				return this;
 			}
 
-			protected File discoverGitPrefix() {
+			protected File discoverGitExe() {
 				return null;
 			}
 
@@ -153,7 +153,7 @@ public class CommitCommandTest extends RepositoryTestCase {
 				return this;
 			}
 
-			protected File discoverGitPrefix() {
+			protected File discoverGitExe() {
 				return null;
 			}
 

org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java

@@ -504,8 +504,16 @@ public abstract class FS {
 		return p.value;
 	}
 
+	/**
+	 * @return the path to the Git executable.
+	 * @since 4.0
+	 */
+	protected abstract File discoverGitExe();
+
 	/** @return the $prefix directory C Git would use. */
-	protected abstract File discoverGitPrefix();
+	protected File discoverGitPrefix() {
+		return resolveGrandparentFile(discoverGitExe());
+	}
 
 	/**
 	 * @param grandchild

org.eclipse.jgit/src/org/eclipse/jgit/util/FS_POSIX.java

@@ -134,28 +134,26 @@ public class FS_POSIX extends FS {
 	}
 
 	@Override
-	protected File discoverGitPrefix() {
+	protected File discoverGitExe() {
 		String path = SystemReader.getInstance().getenv("PATH"); //$NON-NLS-1$
 		File gitExe = searchPath(path, "git"); //$NON-NLS-1$
-		if (gitExe != null)
-			return resolveGrandparentFile(gitExe);
-
-		if (SystemReader.getInstance().isMacOS()) {
-			if (searchPath(path, "bash") != null) { //$NON-NLS-1$
-				// On MacOSX, PATH is shorter when Eclipse is launched from the
-				// Finder than from a terminal. Therefore try to launch bash as a
-				// login shell and search using that.
-				String w = readPipe(userHome(),
-						new String[] { "bash", "--login", "-c", "which git" }, // //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
-						Charset.defaultCharset().name());
-				if (w == null || w.length() == 0)
-					return null;
-				gitExe = new File(w);
-				return resolveGrandparentFile(gitExe);
+
+		if (gitExe == null) {
+			if (SystemReader.getInstance().isMacOS()) {
+				if (searchPath(path, "bash") != null) { //$NON-NLS-1$
+					// On MacOSX, PATH is shorter when Eclipse is launched from the
+					// Finder than from a terminal. Therefore try to launch bash as a
+					// login shell and search using that.
+					String w = readPipe(userHome(),
+							new String[]{"bash", "--login", "-c", "which git"}, // //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
+							Charset.defaultCharset().name());
+					if (!StringUtils.isEmptyOrNull(w))
+						gitExe = new File(w);
+				}
 			}
 		}
 
-		return null;
+		return gitExe;
 	}
 
 	@Override

org.eclipse.jgit/src/org/eclipse/jgit/util/FS_Win32.java

@@ -105,27 +105,24 @@ public class FS_Win32 extends FS {
 	}
 
 	@Override
-	protected File discoverGitPrefix() {
+	protected File discoverGitExe() {
 		String path = SystemReader.getInstance().getenv("PATH"); //$NON-NLS-1$
 		File gitExe = searchPath(path, "git.exe", "git.cmd"); //$NON-NLS-1$ //$NON-NLS-2$
-		if (gitExe != null)
-			return resolveGrandparentFile(gitExe);
-
-		if (searchPath(path, "bash.exe") != null) { //$NON-NLS-1$
-			// This isn't likely to work, but its worth trying:
-			// If bash is in $PATH, git should also be in $PATH.
-			String w = readPipe(userHome(),
-					new String[] { "bash", "--login", "-c", "which git" }, // //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
-					Charset.defaultCharset().name());
-			if (w == null || w.length() == 0)
-				return null;
-			// The path may be in cygwin/msys notation so resolve it right away
-			gitExe = resolve(null, w);
-			if (gitExe != null)
-				return resolveGrandparentFile(gitExe);
+
+		if (gitExe == null) {
+			if (searchPath(path, "bash.exe") != null) { //$NON-NLS-1$
+				// This isn't likely to work, but its worth trying:
+				// If bash is in $PATH, git should also be in $PATH.
+				String w = readPipe(userHome(),
+						new String[]{"bash", "--login", "-c", "which git"}, // //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
+						Charset.defaultCharset().name());
+				if (!StringUtils.isEmptyOrNull(w))
+					// The path may be in cygwin/msys notation so resolve it right away
+					gitExe = resolve(null, w);
+			}
 		}
 
-		return null;
+		return gitExe;
 	}
 
 	@Override