Add second test case for a scenario where Module.locateFile() specifies an already absolute path for loading content in node.js from a different directory, and fix it.

Author: juj

emcc.py

@@ -2559,7 +2559,7 @@ def generate_html(target, options, js_target, target_basename,
             memoryInitializer = Module['memoryInitializerPrefixURL'] + memoryInitializer;
           }
           // If URL to memory initializer is relative, treat it relative with respect to Module['scriptDirectory'], if that is present.
-          if (Module['scriptDirectory'] && !/^(?:[a-z]+:)?\/\//i.test(memoryInitializer)) memoryInitializer = Module['scriptDirectory'] + memoryInitializer;
+          if (Module['scriptDirectory'] && !/^(?:[a-z]+:)?\/\/?/i.test(memoryInitializer)) memoryInitializer = Module['scriptDirectory'] + memoryInitializer;
           Module['memoryInitializerRequestURL'] = memoryInitializer;
           var meminitXHR = Module['memoryInitializerRequest'] = new XMLHttpRequest();
           meminitXHR.open('GET', memoryInitializer, true);

src/preamble.js

@@ -825,8 +825,8 @@ function stackTrace() {
   return demangleAll(js);
 }
 
-function isAbsoluteUrl(url) {
-  return /^(?:[a-z]+:)?\/\//i.test(url);
+function isAbsolutePath(path) {
+  return /^(?:[a-z]+:)?\/\/?/i.test(path);
 }
 
 // Joins relative URL 'b' to URL 'a'. 'a' may be empty, in which case 'b' is returned.
@@ -835,7 +835,7 @@ function joinUrl(a, b) {
 #if ASSERTIONS
   if (a && !a.endsWith('/')) throw 'First parameter to joinUrl() should end in /!';
 #endif
-  return a && !isAbsoluteUrl(b) ? a + b : b;
+  return a && !isAbsolutePath(b) ? a + b : b;
 }
 // Memory management
 

tests/test_other.py

@@ -8142,8 +8142,22 @@ def test_toolchain_profiler(self):
 
   # Tests that Emscripten-compiled applications can be run from a relative path with node command line that is different than the current working directory.
   def test_node_js_run_from_different_directory(self):
+    # Test that .mem.js is loaded up properly even if running the build output from a separate directory.
     os.mkdir('subdir')
     Popen([PYTHON, EMCC, path_from_root('tests', 'hello_world.c'), '-o', os.path.join('subdir', 'a.js'), '-O3']).communicate()
     ret = Popen(NODE_JS + [os.path.join('subdir', 'a.js')], stdout=PIPE).communicate()[0]
+    try_delete('subdir')
+    assert 'hello, world!' in ret
+
+    # Test that the build is loaded properly when Module.locateFile is being used, where Module.locateFile() specifies an absolute path already.
+    os.mkdir('subdir')
+    open(os.path.join('subdir', 'pre.js'), 'w').write('''
+      var Module = {};
+      Module.locateFile = function(f) { return __dirname + '/' + f; }
+    ''')
+
+    Popen([PYTHON, EMCC, path_from_root('tests', 'hello_world.c'), '-o', os.path.join('subdir', 'a.js'), '--pre-js', os.path.join('subdir', 'pre.js'), '-O3']).communicate()
+    ret = Popen(NODE_JS + [os.path.join('subdir', 'a.js')], stdout=PIPE).communicate()[0]
+    try_delete('subdir')
     assert 'hello, world!' in ret