Fix #715: clarify how aborting a running script works

Previously it wasn't clear exactly which parts of the processing model
the vague phrase "abort the script" impacted. This gives us a specific
term that at least outlines the concept, and makes all other places
that are impacted by script abortion reference that term.

source

@@ -84572,12 +84572,14 @@ interface <dfn>NavigatorOnLine</dfn> {
    data-x="js-ScriptEvaluation">ScriptEvaluation</span>(<var>result</var>).</p></li>
 
    <li><p>If <var>evaluationStatus</var> is an abrupt completion, set <var>result</var> to
-   <var>evaluationStatus</var>.[[value]] and go to the step labeled <i>error</i>.</p></li>
-
-   <li><p>If we have reached this step, skip to the step labeled <i>cleanup</i>.</p></li>
+   <var>evaluationStatus</var>.[[value]] and go to the next step (labeled <i>error</i>). If
+   <var>evaluationStatus</var> is a normal completion, or if <span
+   data-x="js-ScriptEvaluation">ScriptEvaluation</span> does not complete because the user agent
+   has <span data-x="abort a running script">aborted the running script</span>, skip to the step
+   labeled <i>cleanup</i>.</p></li>
 
    <li>
-    <p><i>Error</i>: At this point <var>result</var> must be an error object. Perform the following
+    <p><i>Error</i>: At this point <var>result</var> must be an exception. Perform the following
     steps:</p>
 
     <ol>
@@ -84595,10 +84597,10 @@ interface <dfn>NavigatorOnLine</dfn> {
    <li><p><i>Cleanup</i>: <span>Clean up after running script</span> with
    <var>settings</var>.</p></li>
 
-   <li><p>If <var>evaluationStatus</var> exists and is not an abrupt completion, return
+   <li><p>If <var>evaluationStatus</var> exists and is a normal completion, return
    <var>evaluationStatus</var>.[[value]]. Otherwise, script execution was unsuccessful, either
    because an error occurred during parsing, or an exception occurred during evaluation, or because
-   it was aborted prematurely.</p></li>
+   it was <span data-x="abort a running script">aborted prematurely</span>.</p></li>
 
   </ol>
 
@@ -84635,7 +84637,9 @@ interface <dfn>NavigatorOnLine</dfn> {
    </li>
 
    <li><p>If <var>evaluationStatus</var> is an abrupt completion, <span>report the exception</span>
-   given by <var>evaluationStatus</var>.[[value]] for <var>s</var>.</p></li>
+   given by <var>evaluationStatus</var>.[[value]] for <var>s</var>. (Do not perform this step if
+   <span data-x="js-ScriptEvaluation">ScriptEvaluation</span> fails to complete as a result of the
+   user agent <span data-x="abort a running script">aborting the running script</span>.)</p></li>
 
    <li><p><span>Clean up after running script</span> with <var>settings</var>.</p></li>
   </ol>
@@ -84784,10 +84788,18 @@ interface <dfn>NavigatorOnLine</dfn> {
 
   <h5>Killing scripts</h5>
 
+  <p>Although the JavaScript specification does not account for this possibility, it's sometimes
+  necessary to <dfn>abort a running script</dfn>. This causes any <span
+  data-x="js-ScriptEvaluation">ScriptEvaluation</span> or <span
+  data-x="js-ModuleEvaluation">ModuleEvaluation</span> to cease immediately, emptying the
+  <span>JavaScript execution context stack</span> without triggering any of the normal mechanisms
+  like <code data-x="">finally</code> blocks. <ref spec=ECMA262></p>
+
   <p>User agents may impose resource limitations on scripts, for example CPU quotas, memory limits,
   total execution time limits, or bandwidth limitations. When a script exceeds a limit, the user
-  agent may either throw a <code>QuotaExceededError</code> exception, abort the script without an
-  exception, prompt the user, or throttle script execution.</p>
+  agent may either throw a <code>QuotaExceededError</code> exception, <span data-x="abort a running
+  script">abort the script</span> without an exception, prompt the user, or throttle script
+  execution.</p>
 
   <div class="example">
 
@@ -93864,8 +93876,9 @@ interface <dfn>WorkerGlobalScope</dfn> : <span>EventTarget</span> {
     <var>script</var>.</p>
 
     <p class="note">In addition to the usual possibilities of returning a value or failing due to
-    an exception, this could be prematurely aborted by the "<span>kill a worker</span>" or
-    "<span>terminate a worker</span>" algorithms defined below.</p>
+    an exception, this could be <span data-x="abort a running script">prematurely aborted</span> by
+    the "<span>kill a worker</span>" or "<span>terminate a worker</span>" algorithms defined
+    below.</p>
    </li>
 
    <li><p>Enable <var>outside port</var>'s <span>port message queue</span>.</p></li>
@@ -93892,9 +93905,9 @@ interface <dfn>WorkerGlobalScope</dfn> : <span>EventTarget</span> {
     event loop</span> specified by <var>settings object</var> until it is destroyed.</p>
 
     <p class="note">The handling of events or the execution of callbacks by <span
-    data-x="concept-task">tasks</span> run by the <span>event loop</span> might get prematurely
-    aborted by the "<span>kill a worker</span>" or "<span>terminate a worker</span>" algorithms
-    defined below.</p>
+    data-x="concept-task">tasks</span> run by the <span>event loop</span> might get <span
+    data-x="abort a running script">prematurely aborted</span> by the "<span>kill a worker</span>"
+    or "<span>terminate a worker</span>" algorithms defined below.</p>
 
     <p class="note">The worker processing model remains on this step until the event loop is
     destroyed, which happens after the <span data-x="dom-WorkerGlobalScope-closing">closing</span>
@@ -93941,7 +93954,8 @@ interface <dfn>WorkerGlobalScope</dfn> : <span>EventTarget</span> {
 
    <li><p>Wait a user-agent-defined amount of time.</p></li>
 
-   <li><p>Abort the script currently running in the worker.</p></li>
+   <li><p><span data-x="abort a running script">Abort the script</span> currently running in the
+   worker.</p></li>
 
   </ol>
 
@@ -93965,7 +93979,8 @@ interface <dfn>WorkerGlobalScope</dfn> : <span>EventTarget</span> {
    <code>WorkerGlobalScope</code> object's <span>event loop</span>'s <span data-x="task queue">task
    queues</span>, discard them without processing them.</p></li>
 
-   <li><p>Abort the script currently running in the worker.</p></li>
+   <li><p><span data-x="abort a running script">Abort the script</span> currently running in the
+   worker.</p></li>
 
    <li><p>If the worker's <code>WorkerGlobalScope</code> object is actually a
    <code>DedicatedWorkerGlobalScope</code> object (i.e. the worker is a dedicated worker), then
@@ -94518,15 +94533,17 @@ interface <dfn>SharedWorker</dfn> : <span>EventTarget</span> {
       passing the <var>rethrow errors</var> flag.</p>
 
       <p class="note"><var>script</var> will run until it either returns, fails to parse, fails to
-      catch an exception, or gets prematurely aborted by the "<span>kill a worker</span>" or
-      "<span>terminate a worker</span>" algorithms defined above.</p>
+      catch an exception, or gets <span data-x="abort a running script">prematurely aborted</span>
+      by the "<span>kill a worker</span>" or "<span>terminate a worker</span>" algorithms defined
+      above.</p>
 
-      <p>If an exception was thrown or if the script was prematurely aborted, then abort all these
-      steps, letting the exception or aborting continue to be processed by the calling <span
+      <p>If an exception was thrown or if the script was <span data-x="abort a running
+      script">prematurely aborted</span>, then abort all these steps, letting the exception or
+      aborting continue to be processed by the calling <span
       data-x="concept-script">script</span>.</p>
 
-      <p>If the "<span>kill a worker</span>" or "<span>terminate a worker</span>" algorithms abort
-      the script then abort all these steps.</p>
+      <p>If the "<span>kill a worker</span>" or "<span>terminate a worker</span>" algorithms <span
+      data-x="abort a running script">abort</span> the script then abort all these steps.</p>
 
      </li>