From: Date: October 17 2007 9:04am
Subject: bk commit into 5.1 tree (tsmith:1.2581) BUG#20748
List-Archive: http://lists.mysql.com/commits/35732
X-Bug: 20748
Message-Id: <20071017070438.87C997B03@ramayana.hindu.god>

Below is the list of changes that have just been committed into a local
5.1 repository of tsmith. When tsmith does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
For information on how to access the public repository
see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2007-10-17 01:04:34-06:00, tsmith@stripped +1 -0
  Bug #20748: Configuration files should not be read more than once
  
  Change init_default_directories() to remove duplicates from the
  list.
  
  Also, move --sysconfdir=<path> (DEFAULT_SYSCONFDIR) from the end
  to the middle of the list.  $HOME/.my.cnf should be last, so the
  user is able to override the system-wide settings.

  mysys/default.c@stripped, 2007-10-17 01:04:32-06:00, tsmith@stripped +74 -35
    Change order in which defaults files are searched.  Move
    DEFAULT_SYSCONFDIR from the end to the middle (after the hard-
    coded "/etc/" or "C:/", etc.; and before the run-time directories
    (DEFAULT_HOME_ENV, --defaults-extra-file).
    
    Also, don't add duplicate entries in the defaults_directories
    list.  Instead of adding a new duplicate entry, move the
    existing entry to the end of the list.

diff -Nrup a/mysys/default.c b/mysys/default.c
--- a/mysys/default.c	2007-05-10 03:59:25 -06:00
+++ b/mysys/default.c	2007-10-17 01:04:32 -06:00
@@ -960,66 +960,110 @@ static size_t my_get_system_windows_dire
 
 
 /*
-  Create the list of default directories.
+  @brief  Add a single directory to the global default_directories list
 
+  @details  Add the directory to the end of default_directories; if it is
+  already present in the list, move it to the end.
+
+  @param  dir  Directory to add
+
+  @return  void
+*/
+
+static void add_one_default_directory(const char *dir)
+{
+  const char **p;
+  for (p= default_directories; *p; ++p)
+  {
+    if (strcmp(*p, dir) == 0)
+      break;
+  }
+  DBUG_ASSERT(p < default_directories +
+                    array_elements(default_directories) - 1);
+  DBUG_ASSERT(*p == NULL || strcmp(*p, dir) == 0);
+
+  while (*(p + 1))
+  {
+    *p= *(p + 1);
+    ++p;
+  }
+
+  *p= dir;
+}
+
+
+/*
+  @brief Create the list of default directories.
+
+  @details
   On Microsoft Windows, this is:
     1. C:/
     2. GetWindowsDirectory()
     3. GetSystemWindowsDirectory()
-    4. getenv(DEFAULT_HOME_ENV)
-    5. Directory above where the executable is located
-    6. ""
-    7. --sysconfdir=<path>
+    4. --sysconfdir=<path> (compile-time option)
+    5. getenv(DEFAULT_HOME_ENV)
+    6. Directory above where the executable is located
+    7. --defaults-extra-file=<path> (run-time option)
 
   On Novell NetWare, this is:
     1. sys:/etc/
-    2. getenv(DEFAULT_HOME_ENV)
-    3. ""
-    4. --sysconfdir=<path>
+    2. --sysconfdir=<path> (compile-time option)
+    3. getenv(DEFAULT_HOME_ENV)
+    4. --defaults-extra-file=<path> (run-time option)
 
   On OS/2, this is:
     1. getenv(ETC)
     2. /etc/
-    3. getenv(DEFAULT_HOME_ENV)
-    4. ""
-    5. "~/"
-    6. --sysconfdir=<path>
+    3. --sysconfdir=<path> (compile-time option)
+    4. getenv(DEFAULT_HOME_ENV)
+    5. --defaults-extra-file=<path> (run-time option)
+    6. "~/"
 
   Everywhere else, this is:
     1. /etc/
     2. /etc/mysql/
-    3. getenv(DEFAULT_HOME_ENV)
-    4. ""
-    5. "~/"
-    6. --sysconfdir=<path>
+    3. --sysconfdir=<path> (compile-time option)
+    4. getenv(DEFAULT_HOME_ENV)
+    5. --defaults-extra-file=<path> (run-time option)
+    6. "~/"
+
+  On all systems, if a directory is already in the list, it will be moved
+  to the end of the list.  This avoids reading defaults files multiple times,
+  while ensuring the correct precedence.
 
- */
+  @return void
+*/
 
 static void init_default_directories()
 {
-  const char *env, **ptr= default_directories;
+  const char *env;
+
+  bzero(default_directories, sizeof(default_directories));
 
 #ifdef __WIN__
-  *ptr++= "C:/";
+  add_one_default_directory("C:/");
 
   if (GetWindowsDirectory(system_dir,sizeof(system_dir)))
-    *ptr++= (char*)&system_dir;
+    add_one_default_directory((char *)&system_dir);
   if (my_get_system_windows_directory(shared_system_dir,
-                                      sizeof(shared_system_dir)) &&
-      strcmp(system_dir, shared_system_dir))
-    *ptr++= (char *)&shared_system_dir;
+                                      sizeof(shared_system_dir)))
+    add_one_default_directory((char *)&shared_system_dir);
 
 #elif defined(__NETWARE__)
-  *ptr++= "sys:/etc/";
+  add_one_default_directory("sys:/etc/");
 #else
-  *ptr++= "/etc/";
-  *ptr++= "/etc/mysql/";
+  add_one_default_directory("/etc/");
+  add_one_default_directory("/etc/mysql/");
+#endif
+#ifdef DEFAULT_SYSCONFDIR
+  if (DEFAULT_SYSCONFDIR != "")
+    add_one_default_directory(DEFAULT_SYSCONFDIR);
 #endif
   if ((env= getenv(STRINGIFY_ARG(DEFAULT_HOME_ENV))))
-    *ptr++= env;
-  *ptr++= "";			/* Place for defaults_extra_file */
+    add_one_default_directory(env);
+  add_one_default_directory("");			/* Place for defaults_extra_file */
 #if !defined(__WIN__) && !defined(__NETWARE__)
-  *ptr++= "~/";;
+  add_one_default_directory("~/");
 #elif defined(__WIN__)
   if (GetModuleFileName(NULL, config_dir, sizeof(config_dir)))
   {
@@ -1050,12 +1094,7 @@ static void init_default_directories()
         last= end;
       }
     }
-    *ptr++= (char *)&config_dir;
+    add_one_default_directory((char *)&config_dir);
   }
 #endif
-#ifdef DEFAULT_SYSCONFDIR
-  if (DEFAULT_SYSCONFDIR != "")
-    *ptr++= DEFAULT_SYSCONFDIR;
-#endif
-  *ptr= 0;			/* end marker */
 }