diff --git a/browser/base/content/test/Makefile.in b/browser/base/content/test/Makefile.in
index f154e68636e..3c1eb8f9ff8 100644
--- a/browser/base/content/test/Makefile.in
+++ b/browser/base/content/test/Makefile.in
@@ -220,6 +220,7 @@ _BROWSER_FILES = \
                  browser_tabfocus.js \
                  browser_tabs_isActive.js \
                  browser_tabs_owner.js \
+                 browser_urlbarCopying.js \
                  browser_urlbarTrimURLs.js \
                  browser_urlHighlight.js \
                  browser_visibleFindSelection.js \
diff --git a/browser/base/content/test/browser_urlbarCopying.js b/browser/base/content/test/browser_urlbarCopying.js
new file mode 100644
index 00000000000..59e1c4f0175
--- /dev/null
+++ b/browser/base/content/test/browser_urlbarCopying.js
@@ -0,0 +1,165 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const trimPref = "browser.urlbar.trimURLs";
+
+function test() {
+
+  gBrowser.selectedTab = gBrowser.addTab();
+
+  registerCleanupFunction(function () {
+    gBrowser.removeCurrentTab();
+    Services.prefs.clearUserPref(trimPref);
+    URLBarSetURI();
+  });
+
+  Services.prefs.setBoolPref(trimPref, true);
+
+  waitForExplicitFinish();
+
+  nextTest();
+}
+
+var tests = [
+  // pageproxystate="invalid"
+  {
+    setURL: "http://example.com/",
+    expectedURL: "example.com",
+    copyExpected: "example.com"
+  },
+  {
+    copyVal: "<e>xample.com",
+    copyExpected: "e"
+  },
+
+
+  // pageproxystate="valid" from this point on (due to the load)
+  {
+    loadURL: "http://example.com/",
+    expectedURL: "example.com",
+    copyExpected: "http://example.com/"
+  },
+  {
+    copyVal: "<example.co>m",
+    copyExpected: "http://example.co"
+  },
+  {
+    copyVal: "e<x>ample.com",
+    copyExpected: "x"
+  },
+  {
+    copyVal: "<e>xample.com",
+    copyExpected: "http://e"
+  },
+
+  // Test escaping
+  {
+    loadURL: "http://example.com/()%C3%A9",
+    expectedURL: "example.com/()\xe9",
+    copyExpected: "http://example.com/%28%29%C3%A9"
+  },
+  {
+    copyVal: "<example.com/(>)\xe9",
+    copyExpected: "http://example.com/("
+  },
+  {
+    copyVal: "e<xample.com/(>)\xe9",
+    copyExpected: "xample.com/("
+  },
+
+  {
+    loadURL: "http://example.com/%C3%A9%C3%A9",
+    expectedURL: "example.com/\xe9\xe9",
+    copyExpected: "http://example.com/%C3%A9%C3%A9"
+  },
+  {
+    copyVal: "e<xample.com/\xe9>\xe9",
+    copyExpected: "xample.com/\xe9"
+  },
+  {
+    copyVal: "<example.com/\xe9>\xe9",
+    copyExpected: "http://example.com/\xe9"
+  },
+
+  // data: and javsacript: URIs shouldn't be encoded
+  {
+    loadURL: "javascript:('%C3%A9')",
+    expectedURL: "javascript:('\xe9')",
+    copyExpected: "javascript:('\xe9')"
+  },
+  {
+    copyVal: "<javascript:(>'\xe9')",
+    copyExpected: "javascript:("
+  },
+
+  {
+    loadURL: "data:text/html,(%C3%A9)",
+    expectedURL: "data:text/html,(\xe9)",
+    copyExpected: "data:text/html,(\xe9)"
+  },
+  {
+    copyVal: "<data:text/html,(>\xe9)",
+    copyExpected: "data:text/html,("
+  },
+  {
+    copyVal: "data:<text/html,(\xe9>)",
+    copyExpected: "text/html,(\xe9"
+  }
+];
+
+function nextTest() {
+  let test = tests.shift();
+  if (tests.length == 0)
+    runTest(test, finish);
+  else
+    runTest(test, nextTest);
+}
+
+function runTest(test, cb) {
+  function doCheck() {
+    if (test.setURL || test.loadURL)
+      is(gURLBar.value, test.expectedURL, "url bar value set");
+
+    testCopy(test.copyVal, test.copyExpected, cb);
+  }
+
+  if (test.loadURL) {
+    loadURL(test.loadURL, doCheck);
+  } else {
+    if (test.setURL)
+      gURLBar.value = test.setURL;
+    doCheck();
+  }
+}
+
+function testCopy(copyVal, targetValue, cb) {
+  info("Expecting copy of: " + targetValue);
+  waitForClipboard(targetValue, function () {
+    gURLBar.focus();
+    if (copyVal) {
+      let startBracket = copyVal.indexOf("<");
+      let endBracket = copyVal.indexOf(">");
+      if (startBracket == -1 || endBracket == -1 ||
+          startBracket > endBracket ||
+          copyVal.replace("<", "").replace(">", "") != gURLBar.value) {
+        ok(false, "invalid copyVal: " + copyVal);
+      }
+      gURLBar.selectionStart = startBracket;
+      gURLBar.selectionEnd = endBracket - 1;
+    } else {
+      gURLBar.select();
+    }
+
+    goDoCommand("cmd_copy");
+  }, cb, cb);
+}
+
+function loadURL(aURL, aCB) {
+  gBrowser.selectedBrowser.addEventListener("load", function () {
+    gBrowser.selectedBrowser.removeEventListener("load", arguments.callee, true);
+    is(gBrowser.currentURI.spec, aURL, "loaded expected URL");
+    aCB();
+  }, true);
+
+  gBrowser.loadURI(aURL);
+}
diff --git a/browser/base/content/test/browser_urlbarTrimURLs.js b/browser/base/content/test/browser_urlbarTrimURLs.js
index d1faf696433..df70890f7b7 100644
--- a/browser/base/content/test/browser_urlbarTrimURLs.js
+++ b/browser/base/content/test/browser_urlbarTrimURLs.js
@@ -4,7 +4,7 @@
 
 function testVal(originalValue, targetValue) {
   gURLBar.value = originalValue;
-  is(gURLBar.value, targetValue || originalValue, "original value: " + originalValue);
+  is(gURLBar.value, targetValue || originalValue, "url bar value set");
 }
 
 function test() {
@@ -72,7 +72,7 @@ function test() {
 
 function testCopy(originalValue, targetValue, cb) {
   waitForClipboard(targetValue, function () {
-    is(gURLBar.value, originalValue);
+    is(gURLBar.value, originalValue, "url bar copy value set");
 
     gURLBar.focus();
     gURLBar.select();
diff --git a/browser/base/content/urlbarBindings.xml b/browser/base/content/urlbarBindings.xml
index 8cf5333317d..ca4134e519e 100644
--- a/browser/base/content/urlbarBindings.xml
+++ b/browser/base/content/urlbarBindings.xml
@@ -505,23 +505,40 @@
         <body><![CDATA[
           // Grab the actual input field's value, not our value, which could include moz-action:
           var inputVal = this.inputField.value;
-          var val = inputVal.substring(this.selectionStart, this.selectionEnd);
+          var selectedVal = inputVal.substring(this.selectionStart, this.selectionEnd);
 
-          // If the entire value is selected and it's a valid non-javascript,
-          // non-data URI, encode it.
-          if (val == inputVal &&
-              this.getAttribute("pageproxystate") == "valid") {
-            let uri = gBrowser.currentURI;
+          // If the selection doesn't start at the beginning or URL bar is
+          // modified, nothing else to do here.
+          if (this.getAttribute("pageproxystate") != "valid" || this.selectionStart > 0)
+            return selectedVal;
 
-            if (uri && !uri.schemeIs("javascript") && !uri.schemeIs("data")) {
-              val = uri.spec;
+          let uri = gBrowser.currentURI;
 
+          // If the entire URL is selected, just use the actual loaded URI.
+          if (inputVal == selectedVal) {
+            // ... but only if  isn't a javascript: or data: URI, since those
+            // are hard to read when encoded
+            if (!uri.schemeIs("javascript") && !uri.schemeIs("data")) {
               // Parentheses are known to confuse third-party applications (bug 458565).
-              val = val.replace(/[()]/g, function (c) escape(c));
+              selectedVal = uri.spec.replace(/[()]/g, function (c) escape(c));
             }
+
+            return selectedVal;
           }
 
-          return val;
+          // Just the beginning of the URL is selected, check for a trimmed
+          // value
+          let spec = uri.spec;
+          let trimmedSpec = this.trimValue(spec);
+          if (spec != trimmedSpec) {
+            // Prepend the portion that trimValue removed from the beginning.
+            // This assumes trimValue will only truncate the URL at
+            // the beginning or end (or both).
+            let trimmedSegments = spec.split(trimmedSpec);
+            selectedVal = trimmedSegments[0] + selectedVal;
+          }
+
+          return selectedVal;
         ]]></body>
       </method>