diff --git a/common/iobuf.c b/common/iobuf.c
index 35b58ff8d..a6786b199 100644
--- a/common/iobuf.c
+++ b/common/iobuf.c
@@ -170,10 +170,10 @@ static int translate_file_handle (int fd, int for_write);
    underlying file; it just causes any data buffered at the filter A
    to be sent to A's filter function.
 
-   If A is a IOBUF_TEMP filter, then this also enlarges the buffer by
-   IOBUF_BUFFER_SIZE.
+   If A is a IOBUF_OUTPUT_TEMP filter, then this also enlarges the
+   buffer by IOBUF_BUFFER_SIZE.
 
-   May only be called on an IOBUF_OUTPUT or IOBUF_TEMP filters.  */
+   May only be called on an IOBUF_OUTPUT or IOBUF_OUTPUT_TEMP filters.  */
 static int filter_flush (iobuf_t a);
 
 
@@ -1099,7 +1099,8 @@ iobuf_alloc (int use, size_t bufsize)
   iobuf_t a;
   static int number = 0;
 
-  assert (use == IOBUF_INPUT || use == IOBUF_OUTPUT || use == IOBUF_TEMP);
+  assert (use == IOBUF_INPUT
+	  || use == IOBUF_OUTPUT || use == IOBUF_OUTPUT_TEMP);
   if (bufsize == 0)
     {
       log_bug ("iobuf_alloc() passed a bufsize of 0!\n");
@@ -1210,7 +1211,7 @@ iobuf_cancel (iobuf_t a)
 iobuf_t
 iobuf_temp (void)
 {
-  return iobuf_alloc (IOBUF_TEMP, IOBUF_BUFFER_SIZE);
+  return iobuf_alloc (IOBUF_OUTPUT_TEMP, IOBUF_BUFFER_SIZE);
 }
 
 iobuf_t
@@ -1274,6 +1275,8 @@ do_open (const char *fname, int special_filenames,
   int print_only = 0;
   int fd;
 
+  assert (use == IOBUF_INPUT || use == IOBUF_OUTPUT);
+
   if (special_filenames
       /* NULL or '-'.  */
       && (!fname || (*fname == '-' && !fname[1])))
@@ -1600,13 +1603,13 @@ iobuf_push_filter2 (iobuf_t a,
   a->filter_ov = NULL;
   a->filter_ov_owner = 0;
   a->filter_eof = 0;
-  if (a->use == IOBUF_TEMP)
+  if (a->use == IOBUF_OUTPUT_TEMP)
     /* A TEMP filter buffers any data sent to it; it does not forward
        any data down the pipeline.  If we add a new filter to the
        pipeline, it shouldn't also buffer data.  It should send it
        downstream to be buffered.  Thus, the correct type for a filter
-       added in front of an IOBUF_TEMP filter is IOBUF_OUPUT, not
-       IOBUF_TEMP.  */
+       added in front of an IOBUF_OUTPUT_TEMP filter is IOBUF_OUPUT, not
+       IOBUF_OUTPUT_TEMP.  */
     {
       a->use = IOBUF_OUTPUT;
 
@@ -1675,6 +1678,12 @@ pop_filter (iobuf_t a, int (*f) (void *opaque, int control,
   if (DBG_IOBUF)
     log_debug ("iobuf-%d.%d: pop '%s'\n",
 	       a->no, a->subno, iobuf_desc (a));
+  if (a->use == IOBUF_OUTPUT_TEMP)
+    {
+      /* This should be the last filter in the pipeline.  */
+      assert (! a->chain);
+      return 0;
+    }
   if (!a->filter)
     {				/* this is simple */
       b = a->chain;
@@ -1904,7 +1913,7 @@ filter_flush (iobuf_t a)
   size_t len;
   int rc;
 
-  if (a->use == IOBUF_TEMP)
+  if (a->use == IOBUF_OUTPUT_TEMP)
     {				/* increase the temp buffer */
       size_t newsize = a->d.size + IOBUF_BUFFER_SIZE;
 
@@ -1940,7 +1949,7 @@ iobuf_readbyte (iobuf_t a)
 {
   int c;
 
-  if (a->use != IOBUF_INPUT)
+  if (a->use == IOBUF_OUTPUT || a->use == IOBUF_OUTPUT_TEMP)
     {
       log_bug ("iobuf_readbyte called on a non-INPUT pipeline!\n");
       return -1;
@@ -1974,12 +1983,11 @@ iobuf_read (iobuf_t a, void *buffer, unsigned int buflen)
   unsigned char *buf = (unsigned char *)buffer;
   int c, n;
 
-  if (a->use != IOBUF_INPUT)
+  if (a->use == IOBUF_OUTPUT || a->use == IOBUF_OUTPUT_TEMP)
     {
       log_bug ("iobuf_read called on a non-INPUT pipeline!\n");
       return -1;
     }
-  assert (a->use == IOBUF_INPUT);
 
   if (a->nlimit)
     {
@@ -2158,8 +2166,8 @@ iobuf_writestr (iobuf_t a, const char *buf)
 int
 iobuf_write_temp (iobuf_t dest, iobuf_t source)
 {
-  assert (source->use == IOBUF_OUTPUT || source->use == IOBUF_TEMP);
-  assert (dest->use == IOBUF_OUTPUT || dest->use == IOBUF_TEMP);
+  assert (source->use == IOBUF_OUTPUT || source->use == IOBUF_OUTPUT_TEMP);
+  assert (dest->use == IOBUF_OUTPUT || dest->use == IOBUF_OUTPUT_TEMP);
 
   iobuf_flush_temp (source);
   return iobuf_write (dest, source->d.buf, source->d.len);
@@ -2346,7 +2354,7 @@ iobuf_seek (iobuf_t a, off_t newpos)
 {
   file_filter_ctx_t *b = NULL;
 
-  if (a->use != IOBUF_TEMP)
+  if (a->use == IOBUF_OUTPUT || a->use == IOBUF_INPUT)
     {
       /* Find the last filter in the pipeline.  */
       for (; a->chain; a = a->chain)
@@ -2372,8 +2380,8 @@ iobuf_seek (iobuf_t a, off_t newpos)
 	}
 #endif
     }
-  /* Discard the buffer unless it is a temp stream.  */
-  if (a->use != IOBUF_TEMP)
+  /* Discard the buffer it is not a temp stream.  */
+  if (a->use != IOBUF_OUTPUT_TEMP)
     a->d.len = 0;
   a->d.start = 0;
   a->nbytes = 0;
diff --git a/common/iobuf.h b/common/iobuf.h
index 36b14b7d4..b65ea60d7 100644
--- a/common/iobuf.h
+++ b/common/iobuf.h
@@ -58,13 +58,14 @@
    in the iobuf_t.
 
    A pipeline can only be used for reading (IOBUF_INPUT) or for
-   writing (IOBUF_OUTPUT / IOBUF_TEMP).  When reading, data flows from
-   the last filter towards the first.  That is, the user calls
-   iobuf_read(), the module reads from the first filter, which gets
-   its input from the second filter, etc.  When writing, data flows
-   from the first filter towards the last.  In this case, when the
-   user calls iobuf_write(), the data is written to the first filter,
-   which writes the transformed data to the second filter, etc.
+   writing (IOBUF_OUTPUT / IOBUF_OUTPUT_TEMP).  When reading, data
+   flows from the last filter towards the first.  That is, the user
+   calls iobuf_read(), the module reads from the first filter, which
+   gets its input from the second filter, etc.  When writing, data
+   flows from the first filter towards the last.  In this case, when
+   the user calls iobuf_write(), the data is written to the first
+   filter, which writes the transformed data to the second filter,
+   etc.
 
    An iobuf_t contains some state about the filter.  For instance, it
    indicates if the filter has already returned EOF (filter_eof) and
@@ -131,7 +132,7 @@ enum iobuf_use
     IOBUF_OUTPUT=2,
     /* Pipeline is in output mode.  The last filter in the pipeline is
        a temporary buffer that grows as necessary.  */
-    IOBUF_TEMP=3
+    IOBUF_OUTPUT_TEMP
   };
 
 
@@ -142,7 +143,7 @@ typedef struct iobuf_struct *IOBUF;  /* Compatibility with gpg 1.4. */
 struct iobuf_struct
 {
   /* The type of filter.  Either IOBUF_INPUT, IOBUF_OUTPUT or
-     IOBUF_TEMP.  */
+     IOBUF_OUTPUT_TEMP.  */
   enum iobuf_use use;
 
   /* nlimit can be changed using iobuf_set_limit.  If non-zero, it is
@@ -273,7 +274,7 @@ int  iobuf_is_pipe_filename (const char *fname);
    create a new primary source or primary sink, i.e., the last filter
    in the pipeline.
 
-   USE is IOBUF_INPUT, IOBUF_OUTPUT or IOBUF_TEMP.
+   USE is IOBUF_INPUT, IOBUF_OUTPUT or IOBUF_OUTPUT_TEMP.
 
    BUFSIZE is the desired internal buffer size (that is, the size of
    the typical read / write request).  */
@@ -437,7 +438,7 @@ int iobuf_print_chain (iobuf_t a);
 void iobuf_set_limit (iobuf_t a, off_t nlimit);
 
 /* Returns the number of bytes that have been read from the pipeline.
-   Note: the result is undefined for IOBUF_OUTPUT and IOBUF_TEMP
+   Note: the result is undefined for IOBUF_OUTPUT and IOBUF_OUTPUT_TEMP
    pipelines!  */
 off_t iobuf_tell (iobuf_t a);
 
@@ -604,6 +605,6 @@ void iobuf_skip_rest (iobuf_t a, unsigned long n, int partial);
 #define iobuf_get_temp_length(a) ( (a)->d.len )
 
 /* Whether the filter uses an in-memory buffer.  */
-#define iobuf_is_temp(a)	 ( (a)->use == IOBUF_TEMP )
+#define iobuf_is_temp(a)	 ( (a)->use == IOBUF_OUTPUT_TEMP )
 
 #endif /*GNUPG_COMMON_IOBUF_H*/