re PR libfortran/30009 ([4.1 only] Unformatted reads exceeding storage units gives EOF instead of ERR)

2006-12-06  Thomas Koenig  <Thomas.Koenig@online.de>

	PR libfortran/30009
	PR libfortran/30056
	* gfortran.dg/read_eof_4.f90:  Add tests.
	* gfortran.dg/readwrite_unf_direct_eor_1.f90:  New test.
	* gfortran.dg/unf_read_corrupted_1.f90: New test.

2006-12-06  Thomas Koenig  <Thomas.Koenig@online.de>

	PR libfortran/30009
	PR libfortran/30056
	* libgfortran.h:  Add ERROR_CORRUPT_FILE to error_codes.
	* runtime/error.c (translate_error):  Add handling for
	ERROR_CORRUPT_FILE.
	* io/transfer.c (read_block_direct):  Add comment about
	EOR for stream files.
	Remove test for no bytes left for direct access files.
	Generate an ERROR_SHORT_RECORD if the read was short.
	For unformatted sequential files:  Check endfile condition.
	Remove test for no bytes left.  End of file here means
	that the file structure has been corrupted.  Pre-position
	the file for the next record in case of error.
	(write_buf):  Whitespace fix.  Subtract the number of bytes
	written from bytes_left.

From-SVN: r119592

4 files changed, 49 insertions, 32 deletions

diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index 8844e9a..eca621b 100644
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,3 +1,21 @@
+2006-12-06  Thomas Koenig  <Thomas.Koenig@online.de>
+
+	PR libfortran/30009
+	PR libfortran/30056
+	* libgfortran.h:  Add ERROR_CORRUPT_FILE to error_codes.
+	* runtime/error.c (translate_error):  Add handling for
+	ERROR_CORRUPT_FILE.
+	* io/transfer.c (read_block_direct):  Add comment about
+	EOR for stream files.
+	Remove test for no bytes left for direct access files.
+	Generate an ERROR_SHORT_RECORD if the read was short.
+	For unformatted sequential files:  Check endfile condition.
+	Remove test for no bytes left.  End of file here means
+	that the file structure has been corrupted.  Pre-position
+	the file for the next record in case of error.
+	(write_buf):  Whitespace fix.  Subtract the number of bytes
+	written from bytes_left.
+
 2006-12-04  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
 	PR libfortran/30005
diff --git a/libgfortran/io/transfer.c b/libgfortran/io/transfer.c
index 4270d61..163557d 100644
--- a/libgfortran/io/transfer.c
+++ b/libgfortran/io/transfer.c
@@ -374,7 +374,8 @@ read_block_direct (st_parameter_dt *dtp, void *buf, size_t *nbytes)
 
       if (to_read_record != have_read_record)
 	{
-	  /* Short read,  e.g. if we hit EOF.  */
+	  /* Short read,  e.g. if we hit EOF.  For stream files,
+	   we have to set the end-of-file condition.  */
 	  generate_error (&dtp->common, ERROR_END, NULL);
 	  return;
 	}
@@ -388,13 +389,6 @@ read_block_direct (st_parameter_dt *dtp, void *buf, size_t *nbytes)
 	  short_record = 1;
 	  to_read_record = (size_t) dtp->u.p.current_unit->bytes_left;
 	  *nbytes = to_read_record;
-
-	  if (dtp->u.p.current_unit->bytes_left == 0)
-	    {
-	      dtp->u.p.current_unit->endfile = AT_ENDFILE;
-	      generate_error (&dtp->common, ERROR_END, NULL);
-	      return;
-	    }
 	}
 
       else
@@ -411,10 +405,12 @@ read_block_direct (st_parameter_dt *dtp, void *buf, size_t *nbytes)
 	  return;
 	}
 
-      if (to_read_record != *nbytes)  /* Short read, e.g. if we hit EOF.  */
+      if (to_read_record != *nbytes)  
 	{
+	  /* Short read, e.g. if we hit EOF.  Apparently, we read
+	   more than was written to the last record.  */
 	  *nbytes = to_read_record;
-	  generate_error (&dtp->common, ERROR_END, NULL);
+	  generate_error (&dtp->common, ERROR_SHORT_RECORD, NULL);
 	  return;
 	}
 
@@ -430,6 +426,12 @@ read_block_direct (st_parameter_dt *dtp, void *buf, size_t *nbytes)
      until the request has been fulfilled or the record has run out
      of continuation subrecords.  */
 
+  if (dtp->u.p.current_unit->endfile == AT_ENDFILE)
+    {
+      generate_error (&dtp->common, ERROR_END, NULL);
+      return;
+    }
+
   /* Check whether we exceed the total record length.  */
 
   if (dtp->u.p.current_unit->flags.has_recl)
@@ -453,25 +455,7 @@ read_block_direct (st_parameter_dt *dtp, void *buf, size_t *nbytes)
 	{
 	  to_read_subrecord = (size_t) dtp->u.p.current_unit->bytes_left_subrecord;
 	  to_read_record -= to_read_subrecord;
-
-	  if (dtp->u.p.current_unit->bytes_left_subrecord == 0)
-	    {
-	      if (dtp->u.p.current_unit->continued)
-		{
-		  /* Skip to the next subrecord */
-		  next_record_r_unf (dtp, 0);
-		  us_read (dtp, 1);
-		  continue;
-		}
-	      else
-		{
-		  dtp->u.p.current_unit->endfile = AT_ENDFILE;
-		  generate_error (&dtp->common, ERROR_END, NULL);
-		  return;
-		}
-	    }
 	}
-
       else
 	{
 	  to_read_subrecord = to_read_record;
@@ -490,11 +474,15 @@ read_block_direct (st_parameter_dt *dtp, void *buf, size_t *nbytes)
 
       have_read_record += have_read_subrecord;
 
-      if (to_read_subrecord != have_read_subrecord)  /* Short read,
-							e.g. if we hit EOF.  */
+      if (to_read_subrecord != have_read_subrecord)  
+			
 	{
+	  /* Short read, e.g. if we hit EOF.  This means the record
+	     structure has been corrupted, or the trailing record
+	     marker would still be present.  */
+
 	  *nbytes = have_read_record;
-	  generate_error (&dtp->common, ERROR_END, NULL);
+	  generate_error (&dtp->common, ERROR_CORRUPT_FILE, NULL);
 	  return;
 	}
 
@@ -507,6 +495,11 @@ read_block_direct (st_parameter_dt *dtp, void *buf, size_t *nbytes)
 	    }
 	  else
 	    {
+	      /* Let's make sure the file position is correctly set for the
+		 next read statement.  */
+
+	      next_record_r_unf (dtp, 0);
+	      us_read (dtp, 0);
 	      generate_error (&dtp->common, ERROR_SHORT_RECORD, NULL);
 	      return;
 	    }
@@ -637,7 +630,8 @@ write_buf (st_parameter_dt *dtp, void *buf, size_t nbytes)
 	  return FAILURE;
 	}
 
-      dtp->u.p.current_unit->strm_pos += (gfc_offset) nbytes; 
+      dtp->u.p.current_unit->strm_pos += (gfc_offset) nbytes;
+      dtp->u.p.current_unit->bytes_left -= (gfc_offset) nbytes;
 
       return SUCCESS;
 
diff --git a/libgfortran/libgfortran.h b/libgfortran/libgfortran.h
index 644a0ad..c6b31ed 100644
--- a/libgfortran/libgfortran.h
+++ b/libgfortran/libgfortran.h
@@ -416,6 +416,7 @@ typedef enum
   ERROR_ALLOCATION,
   ERROR_DIRECT_EOR,
   ERROR_SHORT_RECORD,
+  ERROR_CORRUPT_FILE,
   ERROR_LAST			/* Not a real error, the last error # + 1.  */
 }
 error_codes;
diff --git a/libgfortran/runtime/error.c b/libgfortran/runtime/error.c
index 122f6d1..3595564 100644
--- a/libgfortran/runtime/error.c
+++ b/libgfortran/runtime/error.c
@@ -440,6 +440,10 @@ translate_error (int code)
       p = "I/O past end of record on unformatted file";
       break;
 
+    case ERROR_CORRUPT_FILE:
+      p = "Unformatted file structure has been corrupted";
+      break;
+
     default:
       p = "Unknown error code";
       break;