Fix stuck multi-file jobs (Issue #5359, Issue #5413)
diff --git a/CHANGES.md b/CHANGES.md
index 472d9a3..8d9a556 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -21,6 +21,8 @@
 - The IPP Everywhere "driver" now properly supports face-up printers
   (Issue #5345)
 - Fixed some typos in the label printer drivers (Issue #5350)
+- Multi-file jobs could get stuck if the backend failed (Issue #5359,
+  Issue #5413)
 - The IPP Everywhere "driver" no longer does local filtering when printing to
   a shared CUPS printer (Issue #5361)
 - The lpadmin command now correctly reports IPP errors when configuring an
diff --git a/backend/socket.c b/backend/socket.c
index 675061d..68379e9 100644
--- a/backend/socket.c
+++ b/backend/socket.c
@@ -1,7 +1,7 @@
 /*
  * AppSocket backend for CUPS.
  *
- * Copyright © 2007-2016 by Apple Inc.
+ * Copyright © 2007-2018 by Apple Inc.
  * Copyright © 1997-2007 by Easy Software Products, all rights reserved.
  *
  * Licensed under Apache License v2.0.  See the file "LICENSE" for more
@@ -397,8 +397,10 @@
       lseek(print_fd, 0, SEEK_SET);
     }
 
-    tbytes = backendRunLoop(print_fd, device_fd, snmp_fd, &(addrlist->addr), 1,
-                            0, backendNetworkSideCB);
+    if ((bytes = backendRunLoop(print_fd, device_fd, snmp_fd, &(addrlist->addr), 1, 0, backendNetworkSideCB)) < 0)
+      tbytes = -1;
+    else
+      tbytes = bytes;
 
     if (print_fd != 0 && tbytes >= 0)
       _cupsLangPrintFilter(stderr, "INFO", _("Print file sent."));
@@ -406,7 +408,7 @@
 
   fputs("STATE: +cups-waiting-for-job-completed\n", stderr);
 
-  if (waiteof)
+  if (waiteof && tbytes >= 0)
   {
    /*
     * Shutdown the socket and wait for the other end to finish...
@@ -443,7 +445,7 @@
   if (print_fd != 0)
     close(print_fd);
 
-  return (CUPS_BACKEND_OK);
+  return (tbytes >= 0 ? CUPS_BACKEND_OK : CUPS_BACKEND_FAILED);
 }
 
 
diff --git a/scheduler/main.c b/scheduler/main.c
index 4b3914a..472b994 100644
--- a/scheduler/main.c
+++ b/scheduler/main.c
@@ -1472,9 +1472,16 @@
               (!job->filters[i] && WIFEXITED(old_status)))
           {				/* Backend and filter didn't crash */
 	    if (job->filters[i])
+	    {
 	      job->status = status;	/* Filter failed */
+	    }
 	    else
+	    {
 	      job->status = -status;	/* Backend failed */
+
+	      if (job->current_file < job->num_files)
+	        cupsdSetJobState(job, IPP_JOB_ABORTED, CUPSD_JOB_FORCE, "Canceling multi-file job due to backend failure.");
+	    }
           }
 
 	  if (job->state_value == IPP_JOB_PROCESSING &&