Bug#39289 libmysqld.a calls exit() upon error

Several functions (mostly in mysqld.cc) directly call
exit() function in case of errors, which is not a desired
behaviour expecially in the embedded-server library.

Fixed by making these functions return error sign instead
of exiting.

per-file comments:
  include/my_getopt.h
Bug#39289 libmysqld.a calls exit() upon error 
  added 'error' retvalue for my_getopt_register_get_addr

  libmysqld/lib_sql.cc
Bug#39289 libmysqld.a calls exit() upon error 
  unireg_clear() function implemented

  mysys/default.c
Bug#39289 libmysqld.a calls exit() upon error 
  error returned instead of exit() call

  mysys/mf_tempdir.c
Bug#39289 libmysqld.a calls exit() upon error 
  free_tmpdir() - fixed so it's not produce crash on uninitialized
    tmpdir structure

  mysys/my_getopt.c
Bug#39289 libmysqld.a calls exit() upon error 
  error returned instead of exit() call

  sql/mysql_priv.h
Bug#39289 libmysqld.a calls exit() upon error 
  unireg_abort definition fixed for the embedded server

  sql/mysqld.cc
Bug#39289 libmysqld.a calls exit() upon error 
  various functions fixed
  error returned instead of exit() call

1 files changed, 5 insertions, 5 deletions

diff --git a/mysys/default.c b/mysys/default.c
index 6b2b31d43ec..c7e1e513e1e 100644
--- a/mysys/default.c
+++ b/mysys/default.c
@@ -144,6 +144,7 @@ static char *remove_end_comment(char *ptr);
   RETURN
     0  ok
     1  given cinf_file doesn't exist
+    2  out of memory
 
     The global variable 'my_defaults_group_suffix' is updated with value for
     --defaults_group_suffix
@@ -190,7 +191,7 @@ int my_search_option_files(const char *conf_file, int *argc, char ***argv,
     if (!(extra_groups= 
 	  (const char**)alloc_root(ctx->alloc,
                                    (2*group->count+1)*sizeof(char*))))
-      goto err;
+      DBUG_RETURN(2);
     
     for (i= 0; i < group->count; i++)
     {
@@ -199,7 +200,7 @@ int my_search_option_files(const char *conf_file, int *argc, char ***argv,
       
       len= strlen(extra_groups[i]);
       if (!(ptr= alloc_root(ctx->alloc, len+instance_len+1)))
-	goto err;
+        DBUG_RETURN(2);
       
       extra_groups[i+group->count]= ptr;
       
@@ -254,12 +255,11 @@ int my_search_option_files(const char *conf_file, int *argc, char ***argv,
     }
   }
 
-  DBUG_RETURN(error);
+  DBUG_RETURN(0);
 
 err:
   fprintf(stderr,"Fatal error in defaults handling. Program aborted\n");
-  exit(1);
-  return 0;					/* Keep compiler happy */
+  DBUG_RETURN(1);
 }