--- a/js/src/shell/js.cpp
+++ b/js/src/shell/js.cpp
@@ -159,16 +159,17 @@ static PRCondVar *gSleepWakeup = NULL;
 #else
 
 static JSRuntime *gRuntime = NULL;
 
 #endif
 
 int gExitCode = 0;
 JSBool gQuitting = JS_FALSE;
+bool gGotError = false;
 FILE *gErrFile = NULL;
 FILE *gOutFile = NULL;
 #ifdef JS_THREADSAFE
 JSObject *gWorkers = NULL;
 js::workers::ThreadPool *gWorkerThreadPool = NULL;
 #endif
 
 static JSBool reportWarnings = JS_TRUE;
@@ -433,19 +434,21 @@ Process(JSContext *cx, JSObject *obj_, c
                 if (ch == '\n' || ch == '\r')
                     break;
             }
         }
         ungetc(ch, file);
 
         int64_t t1 = PRMJ_Now();
         oldopts = JS_GetOptions(cx);
+        gGotError = false;
         JS_SetOptions(cx, oldopts | JSOPTION_COMPILE_N_GO | JSOPTION_NO_SCRIPT_RVAL);
         script = JS_CompileUTF8FileHandle(cx, obj, filename, file);
         JS_SetOptions(cx, oldopts);
+        JS_ASSERT_IF(!script, gGotError);
         if (script && !compileOnly) {
             if (!JS_ExecuteScript(cx, obj, script, NULL)) {
                 if (!gQuitting && !gCanceled)
                     gExitCode = EXITCODE_RUNTIME_ERROR;
             }
             int64_t t2 = PRMJ_Now() - t1;
             if (printTiming)
                 printf("runtime = %.3f ms\n", double(t2) / PRMJ_USEC_PER_MSEC);
@@ -533,22 +536,25 @@ Process(JSContext *cx, JSObject *obj_, c
         uc_buffer = (jschar*)malloc(uc_len * sizeof(jschar));
         JS_DecodeUTF8(cx, buffer, len, uc_buffer, &uc_len);
 
         /* Clear any pending exception from previous failed compiles. */
         JS_ClearPendingException(cx);
 
         /* Even though we're interactive, we have a compile-n-go opportunity. */
         oldopts = JS_GetOptions(cx);
+        gGotError = false;
         if (!compileOnly)
             JS_SetOptions(cx, oldopts | JSOPTION_COMPILE_N_GO);
         script = JS_CompileUCScript(cx, obj, uc_buffer, uc_len, "typein", startline);
         if (!compileOnly)
             JS_SetOptions(cx, oldopts);
 
+        JS_ASSERT_IF(!script, gGotError);
+
         if (script && !compileOnly) {
             ok = JS_ExecuteScript(cx, obj, script, &result);
             if (ok && !JSVAL_IS_VOID(result)) {
                 str = JS_ValueToSource(cx, result);
                 ok = !!str;
                 if (ok) {
                     JSAutoByteString bytes(cx, str);
                     ok = !!bytes;
@@ -4212,16 +4218,18 @@ my_ErrorReporter(JSContext *cx, const ch
         fflush(gErrFile);
         return;
     }
 
     /* Conditionally ignore reported warnings. */
     if (JSREPORT_IS_WARNING(report->flags) && !reportWarnings)
         return;
 
+    gGotError = true;
+
     prefix = NULL;
     if (report->filename)
         prefix = JS_smprintf("%s:", report->filename);
     if (report->lineno) {
         tmp = prefix;
         prefix = JS_smprintf("%s%u: ", tmp ? tmp : "", report->lineno);
         JS_free(cx, tmp);
     }