diff --git a/content/base/test/Makefile.in b/content/base/test/Makefile.in
index a5bc5e6fef2..e0b6c3d25b7 100644
--- a/content/base/test/Makefile.in
+++ b/content/base/test/Makefile.in
@@ -324,6 +324,8 @@ _TEST_FILES = 	test_bug5141.html \
 		bug466409-page.html \
 		bug466409-empty.css \
 		test_bug466409.html \
+		test_bug482935.html \
+		bug482935.sjs \
 		test_classList.html \
 		$(NULL)
 # Disabled; see bug 492181
diff --git a/content/base/test/bug482935.sjs b/content/base/test/bug482935.sjs
new file mode 100644
index 00000000000..9d20eab0f19
--- /dev/null
+++ b/content/base/test/bug482935.sjs
@@ -0,0 +1,12 @@
+function handleRequest(request, response) {
+  var body="initial";
+
+  try {
+      body = request.getHeader("X-Request");
+  } catch(e) {
+    body="request.getHeader() failed! Exception: " + e;
+  }
+
+  response.setHeader("Cache-Control", "max-age=3600");
+  response.bodyOutputStream.write(body, body.length);
+}
diff --git a/content/base/test/test_bug482935.html b/content/base/test/test_bug482935.html
new file mode 100644
index 00000000000..89c3e103900
--- /dev/null
+++ b/content/base/test/test_bug482935.html
@@ -0,0 +1,121 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test bug 482935</title>
+  <script type="text/javascript" src="chrome://mochikit/content/MochiKit/packed.js"></script>
+  <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css" />
+</head>
+<body onload="onWindowLoad()">
+<script class="testbody" type="text/javascript">
+
+var url = "bug482935.sjs";
+
+function clearCache() {
+    netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
+    Components.classes["@mozilla.org/network/cache-service;1"].
+               getService(Components.interfaces.nsICacheService).
+               evictEntries(Components.interfaces.nsICache.STORE_ANYWHERE);
+    netscape.security.PrivilegeManager.disablePrivilege("UniversalXPConnect");
+}
+
+// Tests that the response is cached if the request is cancelled
+// after it has reached state 4
+function testCancelInPhase4() {
+    
+    clearCache();
+
+    // First request - should be loaded from server
+    var xhr = new XMLHttpRequest();
+    xhr.addEventListener("readystatechange", function(e) {
+      if (xhr.readyState >= 4)
+        xhr.abort();
+    }, false);
+
+    xhr.open("GET", url, true);
+    xhr.setRequestHeader("X-Request", "0", false);
+    try { xhr.send(); }
+    catch(e) {
+      is("Nothing", "Exception", "Boom: " + e);
+    }
+
+    setTimeout(function f() {
+      // We know the request is sent, so only these two states are relevant
+      if (xhr.readyState == 2 || xhr.readyState == 3) {
+        setTimeout(f, 100);
+        return;
+      }
+
+      // This request was cancelled, so the responseText should be empty string
+      is(xhr.responseText, "", "Expected empty response to cancelled request");
+
+      // Second request - should be found in cache
+      var xhr2 = new XMLHttpRequest();
+      xhr2.open("GET", url, false); // note : synch-request
+      xhr2.setRequestHeader("X-Request", "1", false);
+
+      try { xhr2.send(); }
+      catch(e) {
+        is(xhr2.status, "200", "Exception!");
+      }
+
+      is(xhr2.responseText, "0", "Received fresh value for second request");
+
+      testCancelBeforePhase4();
+    }, 100);
+}
+
+// Tests that response is NOT cached if the request is cancelled
+// before it has reached state 4
+function testCancelBeforePhase4() {
+
+  clearCache();
+
+  // First request - should be loaded from server
+  var xhr = new XMLHttpRequest();
+  xhr.addEventListener("readystatechange", function(e) {
+    if (xhr.readyState == 3)
+      xhr.abort();
+  }, false);
+
+  xhr.open("GET", url, true);
+  xhr.setRequestHeader("X-Request", "0", false);
+  try { xhr.send(); }
+  catch(e) {
+    is("Nothing", "Exception", "Boom: " + e);
+  }
+
+  setTimeout(function f() {
+    // We know the request is sent, so only this state is relevant
+    if (xhr.readyState == 2) {
+      setTimeout(f, 100);
+      return;
+    }
+
+    // This request was cancelled, so the responseText should be empty string
+    is(xhr.responseText, "", "Expected empty response to cancelled request");
+
+    // Second request - should NOT be found in cache
+    var xhr2 = new XMLHttpRequest();
+    xhr2.open("GET", url, false); // note : synch-request
+    xhr2.setRequestHeader("X-Request", "1", false);
+
+    try { xhr2.send(); }
+    catch(e) {
+      is(xhr2.status, "200", "Exception!");
+    }
+
+    is(xhr2.responseText, "1", "Received cached value for second request");
+
+    SimpleTest.finish();
+  }, 100);
+}
+
+function onWindowLoad() {
+  testCancelInPhase4();
+}
+
+SimpleTest.waitForExplicitFinish();
+</script>
+</body>
+</html>
diff --git a/netwerk/protocol/http/src/nsHttpChannel.cpp b/netwerk/protocol/http/src/nsHttpChannel.cpp
index 87c4aadf6be..ddd363e5bce 100644
--- a/netwerk/protocol/http/src/nsHttpChannel.cpp
+++ b/netwerk/protocol/http/src/nsHttpChannel.cpp
@@ -5124,6 +5124,11 @@ nsHttpChannel::OnStopRequest(nsIRequest *request, nsISupports *ctxt, nsresult st
     LOG(("nsHttpChannel::OnStopRequest [this=%x request=%x status=%x]\n",
         this, request, status));
 
+    // allow content to be cached if it was loaded successfully (bug #482935)
+    PRBool contentComplete = PR_FALSE;
+    if (NS_SUCCEEDED(status))
+        contentComplete = PR_TRUE;
+
     // honor the cancelation status even if the underlying transaction completed.
     if (mCanceled || NS_FAILED(mStatus))
         status = mStatus;
@@ -5214,7 +5219,7 @@ nsHttpChannel::OnStopRequest(nsIRequest *request, nsISupports *ctxt, nsresult st
     }
 
     if (mCacheEntry)
-        CloseCacheEntry(PR_TRUE);
+        CloseCacheEntry(!contentComplete);
 
     if (mOfflineCacheEntry)
         CloseOfflineCacheEntry();
