Bug#25103242: 5.6 DOES NOT BUILD ON FEDORA 25 DUE TO READDIR_R BEING DEPRECATED

Backport from trunk to 5.6 of:

Bug#23708395: GLIBC 2.24 DEPRECATES READDIR_R() BREAKING
              DEBUG BUILD OF MYSQL SERVER

As of glibc 2.24, readdir_r() has been deprecated. This breaks
our debug builds since the deprecation warning is upgraded to
an error during compilation.

This patch fixes the problem by removing use of readdir_r() and
using readdir() instead. This is thread safe as long as readdir()
is only used concurrently on different DIR* - which it is in
our case.

POSIX quote: "The pointer returned by readdir() points to data
which may be overwritten by another call to readdir() on the same
directory stream. This data is not overwritten by another call
to readdir() on a different directory stream."

Change-Id: I85a6f5da2d48c8d5a9804cd6281411d9e757f46c
(cherry picked from commit ba5245e9fef2257d60213076598268f544ca7109)
(cherry picked from commit 865c124d1bdfd4eeee5eb42ea9faa9c8b45bfbb0)
(cherry picked from commit d083887ca7cf90ac370b1a564b5090358f9a097f)

Author: jhauglid

cmake/os/WindowsCache.cmake

@@ -44,7 +44,6 @@ SET(HAVE_CXX_NEW 1 CACHE  INTERNAL "")
 SET(HAVE_CXXABI_H CACHE INTERNAL "")
 SET(HAVE_DECL_MADVISE CACHE  INTERNAL "")
 SET(HAVE_DIRECTIO CACHE  INTERNAL "")
-SET(HAVE_DIRENT_H CACHE  INTERNAL "")
 SET(HAVE_DLERROR CACHE  INTERNAL "")
 SET(HAVE_DLFCN_H CACHE  INTERNAL "")
 SET(HAVE_DLOPEN CACHE  INTERNAL "")
@@ -162,7 +161,6 @@ SET(HAVE_PTHREAD_YIELD_ZERO_ARG CACHE  INTERNAL "")
 SET(HAVE_PUTENV 1 CACHE  INTERNAL "")
 SET(HAVE_PWD_H CACHE  INTERNAL "")
 SET(HAVE_RDTSCLL CACHE  INTERNAL "")
-SET(HAVE_READDIR_R CACHE  INTERNAL "")
 SET(HAVE_READLINK CACHE  INTERNAL "")
 SET(HAVE_READ_REAL_TIME CACHE  INTERNAL "")
 SET(HAVE_REALPATH CACHE  INTERNAL "")

config.h.cmake

@@ -31,7 +31,6 @@
 #cmakedefine HAVE_CXXABI_H 1
 #cmakedefine HAVE_NCURSES_H 1
 #cmakedefine HAVE_NDIR_H 1
-#cmakedefine HAVE_DIRENT_H 1
 #cmakedefine HAVE_DLFCN_H 1
 #cmakedefine HAVE_EXECINFO_H 1
 #cmakedefine HAVE_FCNTL_H 1
@@ -233,7 +232,6 @@
 #cmakedefine HAVE_PUTENV 1
 #cmakedefine HAVE_RE_COMP 1
 #cmakedefine HAVE_REGCOMP 1
-#cmakedefine HAVE_READDIR_R 1
 #cmakedefine HAVE_READLINK 1
 #cmakedefine HAVE_REALPATH 1
 #cmakedefine HAVE_RENAME 1

configure.cmake

@@ -347,7 +347,6 @@ CHECK_INCLUDE_FILES (aio.h HAVE_AIO_H)
 CHECK_INCLUDE_FILES (arpa/inet.h HAVE_ARPA_INET_H)
 CHECK_INCLUDE_FILES (crypt.h HAVE_CRYPT_H)
 CHECK_INCLUDE_FILES (cxxabi.h HAVE_CXXABI_H)
-CHECK_INCLUDE_FILES (dirent.h HAVE_DIRENT_H)
 CHECK_INCLUDE_FILES (dlfcn.h HAVE_DLFCN_H)
 CHECK_INCLUDE_FILES (execinfo.h HAVE_EXECINFO_H)
 CHECK_INCLUDE_FILES (fcntl.h HAVE_FCNTL_H)
@@ -568,7 +567,6 @@ CHECK_FUNCTION_EXISTS (pthread_sigmask HAVE_PTHREAD_SIGMASK)
 CHECK_FUNCTION_EXISTS (pthread_threadmask HAVE_PTHREAD_THREADMASK)
 CHECK_FUNCTION_EXISTS (pthread_yield_np HAVE_PTHREAD_YIELD_NP)
 CHECK_FUNCTION_EXISTS (putenv HAVE_PUTENV)
-CHECK_FUNCTION_EXISTS (readdir_r HAVE_READDIR_R)
 CHECK_FUNCTION_EXISTS (readlink HAVE_READLINK)
 CHECK_FUNCTION_EXISTS (re_comp HAVE_RE_COMP)
 CHECK_FUNCTION_EXISTS (regcomp HAVE_REGCOMP)

include/my_sys.h

@@ -713,7 +713,6 @@ extern size_t cleanup_dirname(char * to,const char *from);
 extern size_t system_filename(char * to,const char *from);
 extern size_t unpack_filename(char * to,const char *from);
 extern char * intern_filename(char * to,const char *from);
-extern char * directory_file_name(char * dst, const char *src);
 extern int pack_filename(char * to, const char *name, size_t max_length);
 extern char * my_path(char * to,const char *progname,
 			 const char *own_pathname_part);

mysys/my_lib.c

@@ -20,33 +20,10 @@
 #include	<m_string.h>
 #include	<my_dir.h>	/* Structs used by my_dir,includes sys/types */
 #include	"mysys_err.h"
-#if defined(HAVE_DIRENT_H)
+#if !defined(_WIN32)
 # include <dirent.h>
-# define NAMLEN(dirent) strlen((dirent)->d_name)
-#else
-# define dirent direct
-# define NAMLEN(dirent) (dirent)->d_namlen
-# if defined(HAVE_SYS_NDIR_H)
-#  include <sys/ndir.h>
-# endif
-# if defined(HAVE_SYS_DIR_H)
-#  include <sys/dir.h>
-# endif
-# if defined(HAVE_NDIR_H)
-#  include <ndir.h>
 # endif
-# if defined(_WIN32)
-# ifdef __BORLANDC__
-# include <dir.h>
-# endif
-# endif
-#endif
 
-#if defined(HAVE_READDIR_R)
-#define READDIR(A,B,C) ((errno=readdir_r(A,B,&C)) != 0 || !C)
-#else
-#define READDIR(A,B,C) (!(C=readdir(A)))
-#endif
 
 /*
   We are assuming that directory we are reading is either has less than 
@@ -88,6 +65,8 @@ static int comp_names(struct fileinfo *a, struct fileinfo *b)
 
 #if !defined(_WIN32)
 
+static char* directory_file_name(char *dst, const char *src);
+
 MY_DIR	*my_dir(const char *path, myf MyFlags)
 {
   char          *buffer;
@@ -96,17 +75,12 @@ MY_DIR	*my_dir(const char *path, myf MyFlags)
   DYNAMIC_ARRAY *dir_entries_storage;
   MEM_ROOT      *names_storage;
   DIR		*dirp;
-  struct dirent *dp;
   char		tmp_path[FN_REFLEN + 2], *tmp_file;
-  char	dirent_tmp[sizeof(struct dirent)+_POSIX_PATH_MAX+1];
+  const struct dirent *dp;
 
   DBUG_ENTER("my_dir");
   DBUG_PRINT("my",("path: '%s' MyFlags: %d",path,MyFlags));
 
-#if !defined(HAVE_READDIR_R)
-  mysql_mutex_lock(&THR_LOCK_open);
-#endif
-
   dirp = opendir(directory_file_name(tmp_path,(char *) path));
 #if defined(__amiga__)
   if ((dirp->dd_fd) < 0)			/* Directory doesn't exists */
@@ -135,9 +109,7 @@ MY_DIR	*my_dir(const char *path, myf MyFlags)
 
   tmp_file=strend(tmp_path);
 
-  dp= (struct dirent*) dirent_tmp;
-  
-  while (!(READDIR(dirp,(struct dirent*) dirent_tmp,dp)))
+  for (dp= readdir(dirp) ; dp; dp= readdir(dirp))
   {
     if (!(finfo.name= strdup_root(names_storage, dp->d_name)))
       goto error;
@@ -162,9 +134,7 @@ MY_DIR	*my_dir(const char *path, myf MyFlags)
   }
 
   (void) closedir(dirp);
-#if !defined(HAVE_READDIR_R)
-  mysql_mutex_unlock(&THR_LOCK_open);
-#endif
+
   result->dir_entry= (FILEINFO *)dir_entries_storage->buffer;
   result->number_off_files= dir_entries_storage->elements;
 
@@ -174,9 +144,6 @@ MY_DIR	*my_dir(const char *path, myf MyFlags)
   DBUG_RETURN(result);
 
  error:
-#if !defined(HAVE_READDIR_R)
-  mysql_mutex_unlock(&THR_LOCK_open);
-#endif
   my_errno=errno;
   if (dirp)
     (void) closedir(dirp);
@@ -198,7 +165,7 @@ MY_DIR	*my_dir(const char *path, myf MyFlags)
  * Returns pointer to dst;
  */
 
-char * directory_file_name (char * dst, const char *src)
+static char* directory_file_name(char *dst, const char *src)
 {
   /* Process as Unix format: just remove test the final slash. */
   char *end;