[PATCH] support: Delete temporary files in LIFO order

[fweimer at redhat dot com (Florian Weimer)]

This is required to remove temporary directories which contain
temporary files.  Previously, FIFO order meant that directory
removal was attempted when the directory still contained files,
which meant that temporary directory cleanup was essentially
unsupported.

2017-05-08  Florian Weimer  <fweimer@redhat.com>

	Delete temporary files in LIFO order.
	* support/temp_file.c (struct temp_name_list): Replace q member
	with next.
	(add_temp_file): Add new file to front of linked list.
	(support_delete_temp_files): Use next member.
	(support_print_temp_files): Likewise.

diff --git a/support/temp_file.c b/support/temp_file.c
index 5950aec..50cbae6 100644
--- a/support/temp_file.c
+++ b/support/temp_file.c
@@ -25,7 +25,6 @@
 #include <support/support.h>
 
 #include <paths.h>
-#include <search.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -33,7 +32,7 @@
 /* List of temporary files.  */
 static struct temp_name_list
 {
-  struct qelem q;
+  struct temp_name_list *next;
   char *name;
 } *temp_name_list;
 
@@ -50,10 +49,8 @@ add_temp_file (const char *name)
   if (newname != NULL)
     {
       newp->name = newname;
-      if (temp_name_list == NULL)
-	temp_name_list = (struct temp_name_list *) &newp->q;
-      else
-	insque (newp, temp_name_list);
+      newp->next = temp_name_list;
+      temp_name_list = newp;
     }
   else
     free (newp);
@@ -105,8 +102,7 @@ support_delete_temp_files (void)
       (void) remove (temp_name_list->name);
       free (temp_name_list->name);
 
-      struct temp_name_list *next
-	= (struct temp_name_list *) temp_name_list->q.q_forw;
+      struct temp_name_list *next = temp_name_list->next;
       free (temp_name_list);
       temp_name_list = next;
     }
@@ -119,9 +115,7 @@ support_print_temp_files (FILE *f)
     {
       struct temp_name_list *n;
       fprintf (f, "temp_files=(\n");
-      for (n = temp_name_list;
-           n != NULL;
-           n = (struct temp_name_list *) n->q.q_forw)
+      for (n = temp_name_list; n != NULL; n = n->next)
         fprintf (f, "  '%s'\n", n->name);
       fprintf (f, ")\n");
     }