diff --git a/lib/jsdoc/path.js b/lib/jsdoc/path.js
index 9a826e8f..eb08089e 100644
--- a/lib/jsdoc/path.js
+++ b/lib/jsdoc/path.js
@@ -42,6 +42,7 @@ function prefixReducer(previousPath, current) {
  *
  * For example, assuming that the current working directory is `/Users/jsdoc`:
  *
+ * + For the single path `foo/bar/baz/qux.js`, the common prefix is `foo/bar/baz/`.
  * + For paths `foo/bar/baz/qux.js`, `foo/bar/baz/quux.js`, and `foo/bar/baz.js`, the common prefix
  * is `/Users/jsdoc/foo/bar/`.
  * + For paths `../jsdoc/foo/bar/baz/qux/quux/test.js`, `/Users/jsdoc/foo/bar/bazzy.js`, and
@@ -53,18 +54,34 @@ function prefixReducer(previousPath, current) {
  * @return {string} The common prefix, or an empty string if there is no common prefix.
  */
 exports.commonPrefix = function(paths) {
-    var common;
+    var segments;
+
+    var prefix = '';
 
     paths = paths || [];
-    common = paths.reduce(prefixReducer, undefined) || [];
 
-    // if there's anything left (other than a placeholder for a leading slash), add a placeholder
-    // for a trailing slash
-    if ( common.length && (common.length > 1 || common[0] !== '') ) {
-        common.push('');
+    // if there's only one path, its resolved dirname (plus a trailing slash) is the common prefix
+    if (paths.length === 1) {
+        prefix = path.resolve(global.env.pwd, paths[0]);
+        if ( path.extname(prefix) ) {
+            prefix = path.dirname(prefix);
+        }
+
+        prefix += path.sep;
+    }
+    else {
+        segments = paths.reduce(prefixReducer, undefined) || [];
+
+        // if there's anything left (other than a placeholder for a leading slash), add a
+        // placeholder for a trailing slash
+        if ( segments.length && (segments.length > 1 || segments[0] !== '') ) {
+            segments.push('');
+        }
+
+        prefix = segments.join(path.sep);
     }
 
-    return common.join(path.sep);
+    return prefix;
 };
 
 /**
diff --git a/lib/jsdoc/tag/dictionary/definitions.js b/lib/jsdoc/tag/dictionary/definitions.js
index 568c8fdd..176aa5fc 100644
--- a/lib/jsdoc/tag/dictionary/definitions.js
+++ b/lib/jsdoc/tag/dictionary/definitions.js
@@ -14,9 +14,13 @@ var Syntax = require('jsdoc/src/syntax').Syntax;
 function filepathMinusPrefix(filepath) {
     var sourceFiles = env.sourceFiles || [];
     var commonPrefix = path.commonPrefix( sourceFiles.concat(env.opts._ || []) );
-    // always use forward slashes
-    var result = (filepath + path.sep).replace(commonPrefix, '')
-        .replace(/\\/g, '/');
+    var result = '';
+
+    if (filepath) {
+        // always use forward slashes
+        result = (filepath + path.sep).replace(commonPrefix, '')
+            .replace(/\\/g, '/');
+    }
 
     if (result.length > 0 && result[result.length - 1] !== '/') {
         result += '/';
diff --git a/rhino/path.js b/rhino/path.js
index 4d29be0b..c4218f93 100644
--- a/rhino/path.js
+++ b/rhino/path.js
@@ -102,12 +102,35 @@ function normalizeArray(parts, allowAboveRoot) {
     return parts;
 }
 
+exports.extname = function(path) {
+  return splitPath(path)[3];
+};
+
 if (isWindows) {
     // Regex to split a windows path into three parts: [*, device, slash,
     // tail] windows-only
     var splitDeviceRe =
         /^([a-zA-Z]:|[\\\/]{2}[^\\\/]+[\\\/][^\\\/]+)?([\\\/])?([\s\S]*?)$/;
 
+    // Regex to split the tail part of the above into [*, dir, basename, ext]
+    var splitTailRe =
+        /^([\s\S]*?)((?:\.{1,2}|[^\\\/]+?|)(\.[^.\/\\]*|))(?:[\\\/]*)$/;
+
+    // Function to split a filename into [root, dir, basename, ext]
+    // windows version
+    var splitPath = function(filename) {
+      // Separate device+slash from tail
+      var result = splitDeviceRe.exec(filename),
+          device = (result[1] || '') + (result[2] || ''),
+          tail = result[3] || '';
+      // Split the tail into dir, basename and extension
+      var result2 = splitTailRe.exec(tail),
+          dir = result2[1],
+          basename = result2[2],
+          ext = result2[3];
+      return [device, dir, basename, ext];
+    };
+
     // path.resolve([from ...], to)
     // windows version
     exports.resolve = function() {
@@ -292,6 +315,14 @@ if (isWindows) {
       return outputParts.join('\\');
     };
 } else {
+    // Split a filename into [root, dir, basename, ext], unix version
+    // 'root' is just a slash, or nothing.
+    var splitPathRe =
+        /^(\/?|)([\s\S]*?)((?:\.{1,2}|[^\/]+?|)(\.[^.\/]*|))(?:[\/]*)$/;
+    var splitPath = function(filename) {
+      return splitPathRe.exec(filename).slice(1);
+    };
+
     // path.resolve([from ...], to)
     // posix version
     exports.resolve = function() {
diff --git a/test/specs/documentation/modules.js b/test/specs/documentation/modules.js
index 63902a69..fd61cda7 100644
--- a/test/specs/documentation/modules.js
+++ b/test/specs/documentation/modules.js
@@ -6,22 +6,31 @@ describe("module names", function() {
 
     var doclets;
 
+    var pwd = env.pwd;
     var srcParser = null;
+    var sourceFiles = env.sourceFiles.slice(0);
     var sourcePaths = env.opts._.slice(0);
 
     beforeEach(function() {
-        env.opts._ = [path.normalize(env.dirname + '/test/fixtures/modules/data/')];
+        env.opts._ = [path.normalize(env.pwd + '/test/fixtures/modules/data/')];
+        env.pwd = env.dirname;
+        env.sourceFiles = [];
         srcParser = jasmine.createParser();
         require('jsdoc/src/handlers').attachTo(srcParser);
     });
 
     afterEach(function() {
         env.opts._ = sourcePaths;
+        env.pwd = pwd;
+        env.sourceFiles = sourceFiles;
     });
 
     it("should create a name from the file path when no documented module name exists", function() {
+        var filename = 'test/fixtures/modules/data/mod-1.js';
+
+        env.sourceFiles.push(filename);
         doclets = srcParser.parse(
-            path.normalize(env.dirname + '/test/fixtures/modules/data/mod-1.js')
+            path.normalize( path.join(env.pwd, filename) )
         );
         expect(doclets.length).toBeGreaterThan(1);
         expect(doclets[0].longname).toEqual('module:mod-1');
@@ -33,8 +42,6 @@ describe("module names", function() {
             var Doclet = require('jsdoc/doclet').Doclet;
             var doclet;
 
-            // setup
-            var sourceFiles = env.sourceFiles.slice(0);
             env.sourceFiles = [
                 'C:\\Users\\Jane Smith\\myproject\\index.js',
                 'C:\\Users\\Jane Smith\\myproject\\lib\\mymodule.js'
@@ -47,16 +54,17 @@ describe("module names", function() {
             });
 
             expect(doclet.name).toBe('lib/mymodule');
-
-            // teardown
-            env.sourceFiles = sourceFiles;
         });
     }
 
     it("should use the documented module name if available", function() {
+        var filename = 'test/fixtures/modules/data/mod-2.js';
+
+        env.sourceFiles.push(filename);
         doclets = srcParser.parse(
-            path.normalize(env.dirname + '/test/fixtures/modules/data/mod-2.js')
+            path.normalize( path.join(env.pwd, filename) )
         );
+
         expect(doclets.length).toBeGreaterThan(1);
         expect(doclets[0].longname).toEqual('module:my/module/name');
     });
diff --git a/test/specs/jsdoc/path.js b/test/specs/jsdoc/path.js
index ea0d0c59..24ed9aeb 100644
--- a/test/specs/jsdoc/path.js
+++ b/test/specs/jsdoc/path.js
@@ -46,6 +46,14 @@ describe('jsdoc/path', function() {
             global.env.pwd = oldPwd;
         });
 
+        it('finds the correct prefix for a single relative path', function() {
+            var paths = [path.join('foo', 'bar', 'baz', 'qux.js')];
+            // we expect a trailing slash
+            var expected = cwd.concat('foo', 'bar', 'baz', '').join(path.sep);
+
+            expect( path.commonPrefix(paths) ).toBe(expected);
+        });
+
         it('finds the correct prefix for a group of relative paths', function() {
             var paths = [
                 path.join('foo', 'bar', 'baz', 'qux.js'),
@@ -58,6 +66,14 @@ describe('jsdoc/path', function() {
             expect( path.commonPrefix(paths) ).toEqual(expected);
         });
 
+        it('finds the correct prefix for a single absolute path', function() {
+            var paths = [cwd.concat('foo', 'bar', 'baz', 'qux.js').join(path.sep)];
+            // we expect a trailing slash
+            var expected = cwd.concat('foo', 'bar', 'baz', '').join(path.sep);
+
+            expect( path.commonPrefix(paths) ).toBe(expected);
+        });
+
         it('finds the correct prefix for a group of absolute paths', function() {
             var paths = [
                 cwd.concat('foo', 'bar', 'baz', 'qux.js').join(path.sep),
@@ -83,6 +99,12 @@ describe('jsdoc/path', function() {
             expect( path.commonPrefix(paths) ).toEqual(expected);
         });
 
+        it('returns an empty string when the paths array is empty', function() {
+            var paths = [];
+
+            expect( path.commonPrefix(paths) ).toBe('');
+        });
+
         // skip on Windows, since the paths share a drive letter at the start
         if (!isWindows) {
             it('returns an empty string when there is no common prefix', function() {
diff --git a/test/specs/tags/overviewtag.js b/test/specs/tags/overviewtag.js
index 22272dbf..d2d85cf1 100644
--- a/test/specs/tags/overviewtag.js
+++ b/test/specs/tags/overviewtag.js
@@ -7,26 +7,42 @@ describe("@overview tag", function() {
 
     var doclets;
 
+    var pwd = env.pwd;
     var srcParser = null;
+    var sourceFiles = env.sourceFiles.slice(0);
     var sourcePaths = env.opts._.slice(0);
 
     beforeEach(function() {
-        env.opts._ = [path.normalize(env.dirname + '/test/fixtures/')];
+        env.opts._ = [path.normalize(env.pwd + '/test/fixtures/')];
+        env.pwd = env.dirname;
+        env.sourceFiles = [];
         srcParser = jasmine.createParser();
         require('jsdoc/src/handlers').attachTo(srcParser);
     });
 
     afterEach(function() {
         env.opts._ = sourcePaths;
+        env.pwd = pwd;
+        env.sourceFiles = sourceFiles;
     });
 
     it('When a file overview tag appears in a doclet, the name of the doclet should contain the path to the file.', function() {
-        doclets = srcParser.parse( path.normalize(env.dirname + '/test/fixtures/file.js') );
+        var filename = 'test/fixtures/file.js';
+
+        env.sourceFiles.push(filename);
+        doclets = srcParser.parse(
+            path.normalize( path.join(env.pwd, filename) )
+        );
         expect(doclets[0].name).toMatch(/^file\.js$/);
     });
 
     it("The name and longname should be equal", function() {
-        doclets = srcParser.parse( path.normalize(env.dirname + '/test/fixtures/file.js') );
+        var filename = 'test/fixtures/file.js';
+
+        env.sourceFiles.push(filename);
+        doclets = srcParser.parse(
+            path.normalize( path.join(env.pwd, filename) )
+        );
         expect(doclets[0].name).toBe(doclets[0].longname);
     });
 });