Overhaul error handling in transform steps (fixes Debian bug #215285)

Three main principles were applied:

1. Check all return codes (this fixes Debian bug #215285, data is lost when
no space left on device).
2. Ensure that resources are not leaked (memory and file descriptors).
3. Consistently use the recode error signalling mechanism: rather than
arbitrarily signalling failure on an I/O error, set error level
RECODE_SYSTEM_ERROR, and signal failure according to fail_level.

It proved to be useful to merge perform_{memory,pass}_sequence.

diff --git a/src/mixed.c b/src/mixed.c
index 29be7d8dd3b1f3ff5a0bfea5a3e5e58e77e65b31..01869e5c41e0d93311af8cbcfddc0c40dd802b60 100644 (file)
--- a/src/mixed.c
+++ b/src/mixed.c
@@ -61,8 +61,7 @@ open_mixed (struct mixed *mixed, RECODE_TASK task)
           !task->output.file)
     {
       recode_perror (NULL, "fopen (%s)", task->output.name);
-      if (task->input.file != stdin)
-       fclose (task->input.file);
+      fclose (task->input.file);
       return false;
     }
   task->output.name = NULL;
@@ -78,15 +77,18 @@ open_mixed (struct mixed *mixed, RECODE_TASK task)
   return true;
 }
 
-static void
+static bool
 close_mixed (struct mixed *mixed)
 {
   /* Clean up.  */
 
-  if (*(mixed->input_name))
-    fclose (mixed->subtask.task->input.file);
-  if (*(mixed->output_name))
-    fclose (mixed->subtask.task->output.file);
+  if (mixed->subtask.task->input.file
+      && fclose (mixed->subtask.task->input.file) != 0)
+    return false;
+  if (mixed->subtask.task->output.file
+      && fclose (mixed->subtask.task->output.file))
+    return false;
+  return true;
 }
 
 static void
@@ -125,70 +127,27 @@ bool
 transform_c_source (RECODE_TASK task)
 {
   struct mixed mixed;
-  bool status = true;
   int character;
 
   if (!open_mixed (&mixed, task))
-    return false;
-
-  character = get_byte (&mixed.subtask);
-  while (character != EOF)
-    switch (character)
-      {
-      case '\'':
-       /* Skip character constant, while copying it untranslated.  */
-
-       put_byte ('\'', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-
-       if (character == EOF)
-         {
-           status = false;
-           break;
-         }
-
-       if (character == '\\')
+    recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
+  else
+    {
+      character = get_byte (&mixed.subtask);
+      while (character != EOF)
+       switch (character)
          {
-           put_byte ('\\', &mixed.subtask);
-           character = get_byte (&mixed.subtask);
-           if (character == EOF)
-             {
-               status = false;
-               break;
-             }
-           put_byte (character, &mixed.subtask);
-           character = get_byte (&mixed.subtask);
-         }
+         case '\'':
+           /* Skip character constant, while copying it untranslated.  */
 
-       if (character == '\'')
-         {
            put_byte ('\'', &mixed.subtask);
            character = get_byte (&mixed.subtask);
-         }
-       else
-         status = false;
-       break;
-
-      case '"':
-       /* Copy the string, translated.  */
 
-       put_byte ('"', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-
-       /* Read in string.  */
-
-       start_accumulation (&mixed);
-
-       while (true)
-         {
            if (character == EOF)
              {
-               recode_accumulated (&mixed);
-               status = false;
+               recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
                break;
              }
-           if (character == '"')
-             break;
 
            if (character == '\\')
              {
@@ -196,90 +155,135 @@ transform_c_source (RECODE_TASK task)
                character = get_byte (&mixed.subtask);
                if (character == EOF)
                  {
-                   recode_accumulated (&mixed);
-                   status = false;
+                   recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
                    break;
                  }
+               put_byte (character, &mixed.subtask);
+               character = get_byte (&mixed.subtask);
              }
-           put_byte (character, &mixed.subtask);
-           character = get_byte (&mixed.subtask);
-         }
-       if (character == EOF)
-         break;
-
-       /* Translate string and dump it.  */
-
-       if (!recode_accumulated (&mixed))
-         status = false;
-       put_byte ('"', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       break;
-
-      case '/':
-       put_byte ('/', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       if (character == EOF)
-         break;
-       if (character == '*')
-         {
-           /* Copy the comment, translated.  */
 
-           put_byte ('*', &mixed.subtask);
+           if (character == '\'')
+             {
+               put_byte ('\'', &mixed.subtask);
+               character = get_byte (&mixed.subtask);
+             }
+           else
+             recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
+           break;
+
+         case '"':
+           /* Copy the string, translated.  */
+
+           put_byte ('"', &mixed.subtask);
            character = get_byte (&mixed.subtask);
 
-           /* Read in comment.  */
+           /* Read in string.  */
 
            start_accumulation (&mixed);
+
            while (true)
              {
                if (character == EOF)
                  {
                    recode_accumulated (&mixed);
-                   status = false;
+                   recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
                    break;
                  }
-               if (character == '*')
+               if (character == '"')
+                 break;
+
+               if (character == '\\')
                  {
+                   put_byte ('\\', &mixed.subtask);
                    character = get_byte (&mixed.subtask);
                    if (character == EOF)
                      {
                        recode_accumulated (&mixed);
-                       status = false;
-                       put_byte ('*', &mixed.subtask);
+                       recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
                        break;
                      }
-                   if (character == '/')
-                     break;
-                   put_byte ('*', &mixed.subtask);
-                 }
-               else
-                 {
-                   put_byte (character, &mixed.subtask);
-                   character = get_byte (&mixed.subtask);
                  }
+               put_byte (character, &mixed.subtask);
+               character = get_byte (&mixed.subtask);
              }
-
            if (character == EOF)
              break;
 
-           /* Translate comment and dump it.  */
+           /* Translate string and dump it.  */
 
            if (!recode_accumulated (&mixed))
-             status = false;
-           put_byte ('*', &mixed.subtask);
+             recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
+           put_byte ('"', &mixed.subtask);
+           character = get_byte (&mixed.subtask);
+           break;
+
+         case '/':
            put_byte ('/', &mixed.subtask);
            character = get_byte (&mixed.subtask);
-         }
-       break;
+           if (character == EOF)
+             break;
+           if (character == '*')
+             {
+               /* Copy the comment, translated.  */
 
-      default:
-       put_byte (character, &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       break;
-      }
+               put_byte ('*', &mixed.subtask);
+               character = get_byte (&mixed.subtask);
 
-  close_mixed (&mixed);
-  return status;
+               /* Read in comment.  */
+
+               start_accumulation (&mixed);
+               while (true)
+                 {
+                   if (character == EOF)
+                     {
+                       recode_accumulated (&mixed);
+                       recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
+                       break;
+                     }
+                   if (character == '*')
+                     {
+                       character = get_byte (&mixed.subtask);
+                       if (character == EOF)
+                         {
+                           recode_accumulated (&mixed);
+                           recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
+                           put_byte ('*', &mixed.subtask);
+                           break;
+                         }
+                       if (character == '/')
+                         break;
+                       put_byte ('*', &mixed.subtask);
+                     }
+                   else
+                     {
+                       put_byte (character, &mixed.subtask);
+                       character = get_byte (&mixed.subtask);
+                     }
+                 }
+
+               if (character == EOF)
+                 break;
+
+               /* Translate comment and dump it.  */
+
+               if (!recode_accumulated (&mixed))
+                 recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
+               put_byte ('*', &mixed.subtask);
+               put_byte ('/', &mixed.subtask);
+               character = get_byte (&mixed.subtask);
+             }
+           break;
+
+         default:
+           put_byte (character, &mixed.subtask);
+           character = get_byte (&mixed.subtask);
+           break;
+         }
+    }
+
+  if (!close_mixed (&mixed))
+    recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
+  SUBTASK_RETURN (&mixed.subtask);
 }
 
 /*------------------------------------------------------------------------.
@@ -298,140 +302,135 @@ bool
 transform_po_source (RECODE_TASK task)
 {
   struct mixed mixed;
-  bool status = true;
   bool recode = false;
   bool msgstr = false;
-  int character;
 
   if (!open_mixed (&mixed, task))
-    return false;
+    recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
+  else
+    {
+      int character = get_byte (&mixed.subtask);
+      while (character != EOF)
+       switch (character)
+         {
+         case '#':
+           /* Copy a comment, recoding only those written by translators.  */
 
-  character = get_byte (&mixed.subtask);
-  while (character != EOF)
-    switch (character)
-      {
-      case '#':
-       /* Copy a comment, recoding only those written by translators.  */
+           put_byte ('#', &mixed.subtask);
+           character = get_byte (&mixed.subtask);
+           if (character == EOF)
+             break;
+           recode = character == ' ' || character == '\t';
 
-       put_byte ('#', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       if (character == EOF)
-         break;
-       recode = character == ' ' || character == '\t';
+           if (recode)
+             start_accumulation (&mixed);
+
+           while (character != '\n' && character != EOF)
+             {
+               put_byte (character, &mixed.subtask);
+               character = get_byte (&mixed.subtask);
+             }
 
-       if (recode)
-         start_accumulation (&mixed);
+           if (recode && !recode_accumulated (&mixed))
+             recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
 
-       while (character != '\n' && character != EOF)
-         {
-           put_byte (character, &mixed.subtask);
+           if (character == EOF)
+             break;
+           put_byte ('\n', &mixed.subtask);
            character = get_byte (&mixed.subtask);
-         }
+           break;
 
-       if (recode)
-         {
-           if (!recode_accumulated (&mixed))
-             status = false;
-         }
+         case 'm':
+           /* Attempt to recognise `msgstr'.  */
 
-       if (character == EOF)
-         break;
-       put_byte ('\n', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       break;
-
-      case 'm':
-       /* Attempt to recognise `msgstr'.  */
-
-       msgstr = false;
-
-       put_byte ('m', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       if (character != 's')
-         break;
-       put_byte ('s', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       if (character != 'g')
-         break;
-       put_byte ('g', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       if (character != 's')
-         break;
-       put_byte ('s', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       if (character != 't')
-         break;
-       put_byte ('t', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       if (character != 'r')
-         break;
-       put_byte ('r', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-
-       msgstr = true;
-       break;
-
-      case '"':
-       /* Copy the string, translating only the `msgstr' ones.  */
-
-       put_byte ('"', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       recode = msgstr;
-
-       if (recode)
-         start_accumulation (&mixed);
-
-       while (true)
-         {
-           if (character == EOF)
-             {
-               if (recode)
-                 {
-                   recode_accumulated (&mixed);
-                   status = false;
-                 }
-               break;
-             }
-           if (character == '"')
+           msgstr = false;
+
+           put_byte ('m', &mixed.subtask);
+           character = get_byte (&mixed.subtask);
+           if (character != 's')
+             break;
+           put_byte ('s', &mixed.subtask);
+           character = get_byte (&mixed.subtask);
+           if (character != 'g')
+             break;
+           put_byte ('g', &mixed.subtask);
+           character = get_byte (&mixed.subtask);
+           if (character != 's')
              break;
+           put_byte ('s', &mixed.subtask);
+           character = get_byte (&mixed.subtask);
+           if (character != 't')
+             break;
+           put_byte ('t', &mixed.subtask);
+           character = get_byte (&mixed.subtask);
+           if (character != 'r')
+             break;
+           put_byte ('r', &mixed.subtask);
+           character = get_byte (&mixed.subtask);
 
-           if (character == '\\')
+           msgstr = true;
+           break;
+
+         case '"':
+           /* Copy the string, translating only the `msgstr' ones.  */
+
+           put_byte ('"', &mixed.subtask);
+           character = get_byte (&mixed.subtask);
+           recode = msgstr;
+
+           if (recode)
+             start_accumulation (&mixed);
+
+           while (true)
              {
-               put_byte ('\\', &mixed.subtask);
-               character = get_byte (&mixed.subtask);
                if (character == EOF)
                  {
                    if (recode)
                      {
                        recode_accumulated (&mixed);
-                       status = false;
+                       recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
                      }
                    break;
                  }
+               if (character == '"')
+                 break;
+
+               if (character == '\\')
+                 {
+                   put_byte ('\\', &mixed.subtask);
+                   character = get_byte (&mixed.subtask);
+                   if (character == EOF)
+                     {
+                       if (recode)
+                         {
+                           recode_accumulated (&mixed);
+                           recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
+                         }
+                       break;
+                     }
+                 }
+               put_byte (character, &mixed.subtask);
+               character = get_byte (&mixed.subtask);
              }
-           put_byte (character, &mixed.subtask);
-           character = get_byte (&mixed.subtask);
-         }
 
-       if (character == EOF)
-         break;
+           if (character == EOF)
+             break;
 
-       if (recode)
-         {
-           if (!recode_accumulated (&mixed))
-             status = false;
-         }
+           if (recode && !recode_accumulated (&mixed))
+             recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
 
-       put_byte ('"', &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       break;
+           put_byte ('"', &mixed.subtask);
+           character = get_byte (&mixed.subtask);
+           break;
 
-      default:
-       put_byte (character, &mixed.subtask);
-       character = get_byte (&mixed.subtask);
-       break;
-      }
+         default:
+           put_byte (character, &mixed.subtask);
+           character = get_byte (&mixed.subtask);
+           break;
+         }
+    }
 
-  close_mixed (&mixed);
-  return status;
+  if (!close_mixed (&mixed))
+    recode_if_nogo (RECODE_SYSTEM_ERROR, &mixed.subtask);
+  SUBTASK_RETURN (&mixed.subtask);
 }

diff --git a/src/task.c b/src/task.c
index 1075525fc36949a0936f94dfbc2969ef756e3047..db7aa2f86924f099aa057b1e1b05c8e009d3c9ad 100644 (file)
--- a/src/task.c
+++ b/src/task.c
@@ -52,21 +52,24 @@ void
 put_byte (int byte, RECODE_SUBTASK subtask)
 {
   if (subtask->output.file)
-    putc (byte, subtask->output.file);
+    {
+      if (putc (byte, subtask->output.file) == EOF)
+        recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+    }
   else if (subtask->output.cursor == subtask->output.limit)
     {
       RECODE_OUTER outer = subtask->task->request->outer;
       size_t old_size = subtask->output.limit - subtask->output.buffer;
       size_t new_size = old_size * 3 / 2 + 40;
 
-      /* FIXME: Rethink about how the error should be reported.  */
-
       if (REALLOC (subtask->output.buffer, new_size, char))
        {
          subtask->output.cursor = subtask->output.buffer + old_size;
          subtask->output.limit = subtask->output.buffer + new_size;
          *subtask->output.cursor++ = byte;
        }
+      else
+        recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
     }
   else
     *subtask->output.cursor++ = byte;
@@ -113,12 +116,14 @@ transform_mere_copy (RECODE_SUBTASK subtask)
        if (fwrite (buffer, BUFFER_SIZE, 1, subtask->output.file) != 1)
          {
            recode_perror (NULL, "fwrite ()");
+           recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
            return false;
          }
       if (size > 0)
        if (fwrite (buffer, size, 1, subtask->output.file) != 1)
          {
            recode_perror (NULL, "fwrite ()");
+           recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
            return false;
          }
     }
@@ -143,6 +148,7 @@ transform_mere_copy (RECODE_SUBTASK subtask)
            != 1)
          {
            recode_perror (NULL, "fwrite ()");
+           recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
            return false;
          }
     }
@@ -205,20 +211,18 @@ transform_byte_to_variable (RECODE_SUBTASK subtask)
 
 /*---------------------------------------------------------------------.
 | Execute the conversion sequence for a recoding TASK, using several   |
-| passes with two alternating memory buffers.  This routine assumes at |
-| least one needed recoding step.                                      |
+| passes with two alternating memory buffers or intermediate files.    |
+| This routine assumes at least one needed recoding step.              |
 `---------------------------------------------------------------------*/
 
 static bool
-perform_memory_sequence (RECODE_TASK task)
+perform_sequence (RECODE_TASK task, enum recode_sequence_strategy strategy)
 {
   RECODE_CONST_REQUEST request = task->request;
   struct recode_subtask subtask_block;
   RECODE_SUBTASK subtask = &subtask_block;
   struct recode_read_write_text input;
   struct recode_read_write_text output;
-  unsigned sequence_index;
-  RECODE_CONST_STEP step;
 
   memset (subtask, 0, sizeof (struct recode_subtask));
   memset (&input, 0, sizeof (struct recode_read_write_text));
@@ -227,11 +231,14 @@ perform_memory_sequence (RECODE_TASK task)
 
   /* Execute one pass for each step of the sequence.  */
 
-  for (sequence_index = 0;
+  for (unsigned sequence_index = 0;
        sequence_index < (unsigned)request->sequence_length
         && task->error_so_far < task->abort_level;
        sequence_index++)
     {
+      RECODE_CONST_STEP step = request->sequence_array + sequence_index;
+      subtask->step = step;
+
       /* Select the input text for this step.  */
 
       if (sequence_index == 0)
@@ -246,7 +253,8 @@ perform_memory_sequence (RECODE_TASK task)
                       subtask->input.file == NULL)
                {
                  recode_perror (NULL, "fopen (%s)", subtask->input.name);
-                 return false;
+                 recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+                  goto exit;
                }
            }
        }
@@ -255,149 +263,42 @@ perform_memory_sequence (RECODE_TASK task)
          subtask->input.buffer = input.buffer;
          subtask->input.cursor = input.buffer;
          subtask->input.limit = input.cursor;
-       }
-
-      /* Select the output text for this step.  */
-
-      if (sequence_index < (unsigned)request->sequence_length - 1)
-       {
-         subtask->output = output;
-         subtask->output.cursor = subtask->output.buffer;
-       }
-      else
-       {
-         subtask->output = task->output;
+         subtask->input.file = input.file;
 
-         if (subtask->output.name)
+         if (strategy == RECODE_SEQUENCE_WITH_FILES &&
+             fseek (subtask->input.file, 0L, SEEK_SET) != 0)
            {
-             if (!*subtask->output.name)
-               subtask->output.file = stdout;
-             else if (subtask->output.file = fopen (subtask->output.name,
-                                                    "w"),
-                      subtask->output.file == NULL)
-               {
-                 recode_perror (NULL, "fopen (%s)", subtask->output.name);
-                 return false;
-               }
+             recode_perror (NULL, "fseek (%s)", subtask->input.name);
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+             goto exit;
            }
        }
 
-      /* Execute one recoding step.  */
-
-      step = request->sequence_array + sequence_index;
-      subtask->step = step;
-      (*step->transform_routine) (subtask);
-
-      /* Post-step clean up.  */
-
-      if (sequence_index == 0)
-       {
-         if (subtask->input.name && *subtask->input.name)
-           fclose (subtask->input.file);
-
-         task->input = subtask->input;
-
-         subtask->input.name = NULL;
-         subtask->input.file = NULL;
-       }
-
-      /* Prepare for next step.  */
-
-      task->swap_input = RECODE_SWAP_UNDECIDED;
+      /* Select the output text for this step.  */
 
       if (sequence_index < (unsigned)request->sequence_length - 1)
        {
-         output = input;
-         input = subtask->output;
-       }
-      else
-       {
-         if (subtask->output.name && *subtask->output.name)
-           fclose (subtask->output.file);
-
-         task->output = subtask->output;
-       }
-    }
-
-  /* Final clean up.  */
-
-  /* FIXME: Maybe we should manage this so it could wait, instead, for
-     avoiding buffer reallocation each time a new recoding is done?  */
-
-  free (input.buffer);
-  free (output.buffer);
-
-  SUBTASK_RETURN (subtask);
-}
-
-/*-------------------------------------------------------------------------.
-| Execute the conversion sequence for a recoding TASK, using several       |
-| passes with two alternating intermediate files.  This routine assumes at |
-| least one needed recoding step.                                          |
-`-------------------------------------------------------------------------*/
-
-static bool
-perform_pass_sequence (RECODE_TASK task)
-{
-  RECODE_CONST_REQUEST request = task->request;
-  struct recode_subtask subtask_block;
-  RECODE_SUBTASK subtask = &subtask_block;
-  struct recode_read_write_text input;
-  struct recode_read_write_text output;
-  unsigned sequence_index;
-  RECODE_CONST_STEP step;
-
-  memset (subtask, 0, sizeof (struct recode_subtask));
-  memset (&input, 0, sizeof (struct recode_read_write_text));
-  memset (&output, 0, sizeof (struct recode_read_write_text));
-  subtask->task = task;
-
-  /* Execute one pass for each step of the sequence.  */
-
-  for (sequence_index = 0;
-       sequence_index < (unsigned)request->sequence_length
-        && task->error_so_far < task->abort_level;
-       sequence_index++)
-    {
-      step = request->sequence_array + sequence_index;
-      subtask->step = step;
-
-      /* Select the input text for this step.  */
-
-      if (sequence_index == 0)
-       {
-         subtask->input = task->input;
+         subtask->output = output;
 
-         if (subtask->input.name)
+         switch (strategy)
            {
-             if (!*subtask->input.name)
-               subtask->input.file = stdin;
-             else if (subtask->input.file = fopen (subtask->input.name, "r"),
-                      subtask->input.file == NULL)
+           case RECODE_SEQUENCE_IN_MEMORY:
+             subtask->output = output;
+             subtask->output.cursor = subtask->output.buffer;
+             break;
+
+           case RECODE_SEQUENCE_WITH_FILES:
+             if (subtask->output.file = tmpfile (), subtask->output.file == NULL)
                {
-                 recode_perror (NULL, "fopen (%s)", subtask->input.name);
+                 recode_perror (NULL, "tmpfile ()");
                  recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
-                 return false;
+                 goto exit;
                }
-           }
-       }
-      else
-       {
-         subtask->input.file = input.file;
-         rewind (subtask->input.file);
-       }
-
-      /* Select the output text for this step.  */
+             break;
 
-      if (sequence_index < (unsigned)request->sequence_length - 1)
-       {
-         subtask->output = output;
-
-         if (subtask->output.file = tmpfile (), subtask->output.file == NULL)
-           {
-             recode_perror (NULL, "tmpfile ()");
-             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
-             return false;
+           default: /* Should never happen */
+             recode_if_nogo (RECODE_INTERNAL_ERROR, subtask);
+             break;
            }
        }
       else
@@ -408,13 +309,12 @@ perform_pass_sequence (RECODE_TASK task)
            {
              if (!*subtask->output.name)
                subtask->output.file = stdout;
-             else if (subtask->output.file = fopen (subtask->output.name,
-                                                    "w"),
+             else if (subtask->output.file = fopen (subtask->output.name, "w"),
                       subtask->output.file == NULL)
                {
                  recode_perror (NULL, "fopen (%s)", subtask->output.name);
                  recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
-                 return false;
+                  goto exit;
                }
            }
        }
@@ -425,21 +325,23 @@ perform_pass_sequence (RECODE_TASK task)
 
       /* Post-step clean up.  */
 
-      if (sequence_index == 0)
+      if (subtask->input.file)
        {
-         if (subtask->input.name && *subtask->input.name)
-           fclose (subtask->input.file);
+         FILE *fp = subtask->input.file;
 
-         task->input = subtask->input;
-
-         subtask->input.name = NULL;
-         subtask->input.buffer = NULL;
-         subtask->input.cursor = NULL;
-         subtask->input.limit = NULL;
+         subtask->input.file = NULL;
+         if (fclose (fp) != 0)
+           {
+             recode_perror (NULL, "fclose (%s)", subtask->input.name);
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+             goto exit;
+           }
        }
-      else
+
+      if (sequence_index == 0)
        {
-         fclose (subtask->input.file);
+         task->input = subtask->input;
+         memset (&subtask->input, 0, sizeof (struct recode_read_write_text));
        }
 
       /* Prepare for next step.  */
@@ -451,15 +353,27 @@ perform_pass_sequence (RECODE_TASK task)
          output = input;
          input = subtask->output;
        }
-      else
-       {
-         if (subtask->output.name && *subtask->output.name)
-           fclose (subtask->output.file);
+    }
 
-         task->output = subtask->output;
-       }
+  /* Final clean up.  */
+ exit:
+
+  if (subtask->input.file && fclose (subtask->input.file) != 0)
+    {
+      recode_perror (NULL, "fclose (%s)", subtask->input.name);
+      recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+    }
+
+  if (subtask->output.file && fclose (subtask->output.file) != 0)
+    {
+      recode_perror (NULL, "fclose (%s)", subtask->output.name);
+      recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
     }
 
+  free (input.buffer);
+  free (output.buffer);
+
+  task->output = subtask->output;
   SUBTASK_RETURN (subtask);
 }
 
@@ -522,12 +436,14 @@ perform_pipe_sequence (RECODE_TASK task)
       if (pipe (pipe_pair) < 0)
        {
          recode_perror (outer, "pipe ()");
-         return false;
+         recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+         SUBTASK_RETURN (subtask);
        }
       if (child_process = fork (), child_process < 0)
        {
          recode_perror (outer, "fork ()");
-         return false;
+         recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+         SUBTASK_RETURN (subtask);
        }
       if (child_process == 0)
        {
@@ -537,23 +453,31 @@ perform_pipe_sequence (RECODE_TASK task)
          if (close (pipe_pair[1]) < 0)
            {
              recode_perror (outer, "close ()");
-             return false;
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+             SUBTASK_RETURN (subtask);
            }
          if (subtask->input.file = fdopen (pipe_pair[0], "r"),
              subtask->input.file == NULL)
            {
              recode_perror (outer, "fdopen ()");
-             return false;
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+             SUBTASK_RETURN (subtask);
            }
 
          step = request->sequence_array + sequence_index;
          subtask->step = step;
          (*step->transform_routine) (subtask);
 
-         fclose (subtask->input.file);
-         if (sequence_index < (unsigned)request->sequence_length - 1
-             || *subtask->output.name)
-           fclose (subtask->output.file);
+         if (fclose (subtask->input.file) != 0)
+           {
+              recode_perror (NULL, "fclose (%s)", subtask->input.name);
+              recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+           }
+         if (subtask->output.file && fclose (subtask->output.file) != 0)
+            {
+              recode_perror (NULL, "fclose (%s)", subtask->output.name);
+              recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+            }
 
          exit (task->error_so_far < task->fail_level ? EXIT_SUCCESS
                : EXIT_FAILURE);
@@ -565,17 +489,20 @@ perform_pipe_sequence (RECODE_TASK task)
          if (dup2 (pipe_pair[1], fileno (subtask->output.file)) < 0)
            {
              recode_perror (outer, "dup2 ()");
-             return false;
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+             SUBTASK_RETURN (subtask);
            }
          if (close (pipe_pair[0]) < 0)
            {
              recode_perror (outer, "close ()");
-             return false;
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+             SUBTASK_RETURN (subtask);
            }
          if (close (pipe_pair[1]) < 0)
            {
              recode_perror (outer, "close ()");
-             return false;
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+             SUBTASK_RETURN (subtask);
            }
        }
     }
@@ -589,17 +516,23 @@ perform_pipe_sequence (RECODE_TASK task)
           subtask->input.file == NULL)
     {
       recode_perror (outer, "fopen (%s)", subtask->input.name);
-      return false;
+      SUBTASK_RETURN (subtask);
     }
 
   step = request->sequence_array;
   subtask->step = step;
   (*step->transform_routine) (subtask);
 
-  if (*subtask->input.name)
-    fclose (subtask->input.file);
-
-  fclose (subtask->output.file);
+  if (subtask->input.file && fclose (subtask->input.file) != 0)
+    {
+      recode_perror (NULL, "fclose (%s)", subtask->input.name);
+      recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+    }
+  if (subtask->output.file && fclose (subtask->output.file) != 0)
+    {
+      recode_perror (NULL, "fclose (%s)", subtask->output.name);
+      recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+    }
 
   /* Wait on all children, mainly to avoid synchronisation problems on
      output file contents, but also to reduce the number of zombie
@@ -724,10 +657,18 @@ perform_pipe_sequence (RECODE_TASK task)
          subtask->step = step;
          (*step->transform_routine) (subtask);
 
-         fclose (subtask->input.file);
-         if (sequence_index < request->sequence_length - 1
-             || *subtask->output.name)
-           fclose (subtask->output.file);
+         if (subtask->input.file && fclose (subtask->input.file) != 0)
+           {
+              recode_perror (NULL, "fclose (%s)", subtask->input.name);
+              recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+              return false;
+           }
+         if (subtask->output.file && fclose (subtask->output.file) != 0)
+            {
+              recode_perror (NULL, "fclose (%s)", subtask->output.name);
+              recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+              return false;
+            }
 
          exit (task->error_so_far < task->fail_level ? EXIT_SUCCESS
                : EXIT_FAILURE);
@@ -739,16 +680,19 @@ perform_pipe_sequence (RECODE_TASK task)
          if (dup2 (pipe_pair[1], fileno (subtask->output.file)) < 0)
            {
              recode_perror (outer, "dup2 ()");
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
              return false;
            }
          if (close (pipe_pair[0]) < 0)
            {
              recode_perror (outer, "close ()");
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
              return false;
            }
          if (close (pipe_pair[1]) < 0)
            {
              recode_perror (outer, "close ()");
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
              return false;
            }
        }
@@ -766,6 +710,7 @@ perform_pipe_sequence (RECODE_TASK task)
           subtask->input.file == NULL)
     {
       recode_perror (outer, "fopen (%s)", subtask->input.name);
+      recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
       return false;
     }
 
@@ -773,10 +718,19 @@ perform_pipe_sequence (RECODE_TASK task)
   subtask->step = step;
   (*step->transform_routine) (subtask);
 
-  if (*subtask->input.name)
-    fclose (subtask->input.file);
+  if (subtask->input.file && fclose (subtask->input.file) != 0)
+    {
+      recode_perror (NULL, "fclose (%s)", subtask->input.name);
+      recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+      return false;
+    }
 
-  fclose (subtask->output.file);
+  if (subtask->output.file && fclose (subtask->output.file) != 0)
+    {
+      recode_perror (NULL, "fclose (%s)", subtask->output.name);
+      recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+      return false;
+    }
 
   /* Wait on all children, mainly to avoid synchronisation problems on
      output file contents, but also to reduce the number of zombie
@@ -792,6 +746,7 @@ perform_pipe_sequence (RECODE_TASK task)
        {
          recode_error (outer, _("Child process wait status is 0x%0.2x"),
                        wait_status);
+         recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
          return false;
        }
 
@@ -919,13 +874,13 @@ recode_perform_task (RECODE_TASK task)
 
        if ((task->input.name || task->input.file)
            && (task->output.name || task->output.file))
-         success = perform_pass_sequence (task);
+         success = perform_sequence (task, RECODE_SEQUENCE_WITH_FILES);
        else
-         success = perform_memory_sequence (task);
+         success = perform_sequence (task, RECODE_SEQUENCE_IN_MEMORY);
        break;
 
       case RECODE_SEQUENCE_IN_MEMORY:
-       success = perform_memory_sequence (task);
+       success = perform_sequence (task, RECODE_SEQUENCE_IN_MEMORY);
        break;
 
       case RECODE_SEQUENCE_WITH_PIPE:
@@ -937,7 +892,7 @@ recode_perform_task (RECODE_TASK task)
 #endif
 
       case RECODE_SEQUENCE_WITH_FILES:
-       success = perform_pass_sequence (task);
+       success = perform_sequence (task, RECODE_SEQUENCE_WITH_FILES);
        break;
 
       default:
@@ -963,6 +918,7 @@ recode_perform_task (RECODE_TASK task)
                   subtask->input.file == NULL)
            {
              recode_perror (NULL, "fopen (%s)", subtask->input.name);
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
              return false;
            }
        }
@@ -975,6 +931,7 @@ recode_perform_task (RECODE_TASK task)
                   subtask->output.file == NULL)
            {
              recode_perror (NULL, "fopen (%s)", subtask->output.name);
+             recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
              return false;
            }
        }
@@ -991,10 +948,18 @@ recode_perform_task (RECODE_TASK task)
 
       task->output = subtask->output;
 
-      if (subtask->input.name && *subtask->input.name)
-       fclose (subtask->input.file);
-      if (subtask->output.name && *subtask->output.name)
-       fclose (subtask->output.file);
+      if (subtask->input.file && fclose (subtask->input.file) != 0)
+       {
+          recode_perror (NULL, "fclose (%s)", subtask->input.name);
+          recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+          return false;
+       }
+      if (subtask->output.file && fclose (subtask->output.file) != 0)
+        {
+          recode_perror (NULL, "fclose (%s)", subtask->output.name);
+          recode_if_nogo (RECODE_SYSTEM_ERROR, subtask);
+          return false;
+        }
     }
 
   return success;