Fix a couple of places that would loop forever if attempts to read a stdio file

set ferror() but never set feof().  This is known to be the case for recent
glibc when trying to read a directory as a file, and might be true for other
platforms/cases too.  Per report from Ed L.  (There is more that we ought to
do about his report, but this is one easily identifiable issue.)

src/backend/libpq/hba.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/libpq/hba.c,v 1.199 2010/03/01 16:02:01 mha Exp $
+ *	  $PostgreSQL: pgsql/src/backend/libpq/hba.c,v 1.200 2010/03/03 20:31:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -404,7 +404,7 @@ tokenize_file(const char *filename, FILE *file,
 
 	*lines = *line_nums = NIL;
 
-	while (!feof(file))
+	while (!feof(file) && !ferror(file))
 	{
 		buf = next_token_expand(filename, file);
 

src/interfaces/libpq/fe-connect.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.388 2010/02/26 02:01:32 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.389 2010/03/03 20:31:09 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -4394,7 +4394,7 @@ PasswordFromFile(char *hostname, char *port, char *dbname, char *username)
 	if (fp == NULL)
 		return NULL;
 
-	while (!feof(fp))
+	while (!feof(fp) && !ferror(fp))
 	{
 		char	   *t = buf,
 				   *ret;