1 files changed, 39 insertions, 29 deletions

diff --git a/base/gdevepo.c b/base/gdevepo.c
index e3454273..7c9eb0b7 100644
--- a/base/gdevepo.c
+++ b/base/gdevepo.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2020 Artifex Software, Inc.
+/* Copyright (C) 2001-2021 Artifex Software, Inc.
    All Rights Reserved.
 
    This software is provided AS-IS with no warranty, either express or
@@ -193,16 +193,23 @@ gx_device_epo gs_epo_device =
 #undef MAX_COORD
 #undef MAX_RESOLUTION
 
-static bool
-is_device_installed(gx_device *dev, const char *name)
+/* Starting at the top of the device chain (top parent) find	*/
+/* and return the epo device, or NULL if not found.		*/
+static gx_device *
+find_installed_epo_device(gx_device *dev)
 {
-    while (dev) {
-        if (!strcmp(dev->dname, name)) {
-            return true;
+    gx_device *next_dev = dev;
+
+    while (next_dev->parent != NULL)
+        next_dev = next_dev->parent;
+
+    while (next_dev) {
+        if (next_dev->procs.fillpage == epo_fillpage) {
+            return next_dev;
         }
-        dev = dev->child;
+        next_dev = next_dev->child;
     }
-    return false;
+    return NULL;
 }
 
 /* See if this is a device we can optimize
@@ -212,7 +219,12 @@ is_device_installed(gx_device *dev, const char *name)
 static bool
 device_wants_optimization(gx_device *dev)
 {
-    return (!gs_is_null_device(dev) && dev_proc(dev, fillpage) == gx_default_fillpage);
+    gx_device *terminal = dev;
+
+    while(terminal->child != NULL)
+        terminal = terminal->child;
+
+    return (!gs_is_null_device(terminal) && dev_proc(terminal, fillpage) == gx_default_fillpage);
 }
 
 /* Use this when debugging to enable/disable epo
@@ -228,33 +240,31 @@ int
 epo_check_and_install(gx_device *dev)
 {
     int code = 0;
-    bool is_installed;
+    gx_device *installed_epo_device = NULL;
     bool can_optimize = false;
-    
+
     /* Debugging mode to totally disable this */
     if (gs_debug_c(gs_debug_flag_epo_disable)) {
         return code;
     }
-    
+
     DPRINTF1(dev->memory, "current device is %s\n", dev->dname);
 
-    is_installed = is_device_installed(dev, EPO_DEVICENAME);
-    
-    if (is_installed) {
+    installed_epo_device = find_installed_epo_device(dev);
+
+    if (installed_epo_device != NULL) {
         DPRINTF1(dev->memory, "device %s already installed\n", EPO_DEVICENAME);
         /* This is looking for the case where the device
          * changed into something we can't optimize, after it was already installed
          * (could be clist or some other weird thing)
          */
-        if (dev->child) {
-            can_optimize = device_wants_optimization(dev->child);
+        if (installed_epo_device->child) {
+            can_optimize = device_wants_optimization(installed_epo_device->child);
         }
         if (!can_optimize) {
-            DPRINTF1(dev->memory, "child %s can't be optimized, uninstalling\n", dev->child->dname);
-            /* Not doing any pending fillpages because we are about to do
-             * a fillpage anyway
-             */
-            gx_device_unsubclass(dev);        
+            DPRINTF1(dev->memory, "child %s can't be optimized, uninstalling\n", installed_epo_device->child->dname);
+            /* Not doing any pending fillpages because we are about to do a fillpage anyway */
+            gx_device_unsubclass(installed_epo_device);
             return code;
         }
     } else {
@@ -262,7 +272,7 @@ epo_check_and_install(gx_device *dev)
     }
 
     /* Already installed, nothing to do */
-    if (is_installed) {
+    if (installed_epo_device != NULL) {
         return code;
     }
 
@@ -278,7 +288,7 @@ epo_check_and_install(gx_device *dev)
         DPRINTF1(dev->memory, "ERROR installing device %s\n", EPO_DEVICENAME);
         return code;
     }
-        
+
     DPRINTF1(dev->memory, "SUCCESS installed device %s\n", dev->dname);
     return code;
 }
@@ -288,7 +298,7 @@ epo_handle_erase_page(gx_device *dev)
 {
     erasepage_subclass_data *data = (erasepage_subclass_data *)dev->subclass_data;
     int code = 0;
-    
+
     if (gs_debug_c(gs_debug_flag_epo_install_only)) {
         gx_device_unsubclass(dev);
         DPRINTF1(dev->memory, "Uninstall erasepage, device=%s\n", dev->dname);
@@ -314,7 +324,7 @@ epo_handle_erase_page(gx_device *dev)
 int epo_fillpage(gx_device *dev, gs_gstate * pgs, gx_device_color *pdevc)
 {
     erasepage_subclass_data *data = (erasepage_subclass_data *)dev->subclass_data;
-    
+
     if (gs_debug_c(gs_debug_flag_epo_install_only)) {
         return default_subclass_fillpage(dev, pgs, pdevc);
     }
@@ -322,13 +332,13 @@ int epo_fillpage(gx_device *dev, gs_gstate * pgs, gx_device_color *pdevc)
     /* If color is not pure, don't defer this, uninstall and do it now */
     if (!color_is_pure(pdevc)) {
         DPRINTF(dev->memory, "epo_fillpage(), color is not pure, uninstalling\n");
-        gx_device_unsubclass(dev);        
+        gx_device_unsubclass(dev);
         return dev_proc(dev, fillpage)(dev, pgs, pdevc);
     }
-    
+
     /* Save the color being requested, and swallow the fillpage */
     data->last_color = pdevc->colors.pure;
-    
+
     DPRINTF(dev->memory, "Swallowing fillpage\n");
     return 0;
 }