Associate a charset directly with its number in the Index file, and

propogate those changes through the code.  This is so that there can
be holes in the list of charsets without breaking old tables.


configure.in:
  - changed pattern for getting number from charsets Index file
mysys/charset.c:
  - changed from using a TYPELIB to a CS_ID struct, so both the name
    and the number of a charset is stored in available_charsets
sql/share/charsets/Index:
  - made the number a real part of the Index file, not just a comment
sql/share/charsets/README:
  - order is no longer significant, but each charset must be paired
    with its number

1 files changed, 61 insertions, 34 deletions

diff --git a/mysys/charset.c b/mysys/charset.c
index bf51184589c..0cc85058eeb 100644
--- a/mysys/charset.c
+++ b/mysys/charset.c
@@ -21,9 +21,14 @@
 #include <m_string.h>
 #include <my_dir.h>
 
+typedef struct cs_id_st {
+  char *name;
+  uint number;
+} CS_ID;
+
 const char *charsets_dir = NULL;
 static DYNAMIC_ARRAY cs_info_table;
-static TYPELIB available_charsets;
+static CS_ID *available_charsets;
 static int charset_initialized=0;
 
 #define MAX_LINE  1024
@@ -46,6 +51,24 @@ uint compiled_charset_number(const char *name);
 const char *compiled_charset_name(uint charset_number);
 
 
+static uint num_from_csname(CS_ID *cs, const char *name)
+{
+  CS_ID *c;
+  for (c = cs; c; ++c)
+    if (!strcmp(c->name, name))
+      return c->number;
+  return 0;   /* this mimics find_type() */
+}
+
+static char *name_from_csnum(CS_ID *cs, uint number)
+{
+  CS_ID *c;
+  for (c = cs; c; ++c)
+    if (c->number == number)
+      return c->name;
+  return "?";   /* this mimics find_type() */
+}
+
 static my_bool get_word(struct simpleconfig_buf_st *fb, char *buf)
 {
   char *endptr=fb->p;
@@ -92,12 +115,12 @@ static char *get_charsets_dir(char *buf)
 }
 
 
-static my_bool read_charset_index(TYPELIB *charsets, myf myflags)
+static my_bool read_charset_index(CS_ID **charsets, myf myflags)
 {
   struct simpleconfig_buf_st fb;
-  char buf[MAX_LINE];
+  char buf[MAX_LINE], num_buf[MAX_LINE];
   DYNAMIC_ARRAY cs;
-  my_string s;
+  CS_ID *csid;
 
   strmov(get_charsets_dir(buf), "Index");
 
@@ -106,36 +129,42 @@ static my_bool read_charset_index(TYPELIB *charsets, myf myflags)
   fb.buf[0] = '\0';
   fb.p = fb.buf;
 
-  if (init_dynamic_array(&cs, sizeof(my_string), 32, 32))
+  if (init_dynamic_array(&cs, sizeof(CS_ID *), 32, 32))
     return TRUE;
 
-  while (!get_word(&fb, buf))
+  while (!get_word(&fb, buf) && !get_word(&fb, num_buf))
   {
+    uint csnum;
     uint length;
-    if (!(s= (char*) my_once_alloc(length= (uint) strlen(buf)+1, myflags)))
+
+    if (!(csnum = atoi(num_buf)))
     {
+      /* corrupt Index file */
       my_fclose(fb.f,myflags);
       return TRUE;
     }
-    memcpy(s,buf,length);
-    insert_dynamic(&cs, (gptr) &s);
+
+    if (!(csid = (CS_ID*) my_once_alloc(sizeof(CS_ID), myflags)) ||
+        !(csid->name=
+           (char*) my_once_alloc(length= (uint) strlen(buf)+1, myflags)))
+    {
+      my_fclose(fb.f,myflags);
+      return TRUE;
+    }
+    memcpy(csid->name,buf,length);
+    csid->number = csnum;
+
+    insert_dynamic(&cs, (gptr) &csid);
   }
   my_fclose(fb.f,myflags);
 
-  /* I seriously doubt this is the best way to initialize this
-   * TYPELIB from the Index file.  But it's the best way I could
-   * come up with right now. */
 
-  charsets->count = cs.elements;
-  charsets->name  = "";
-  if (!(charsets->type_names =
-	(const char **) my_once_alloc((cs.elements + 1) * sizeof(const char *),
-				      myflags)))
+  if (!(*charsets =
+      (CS_ID *) my_once_alloc((cs.elements + 1) * sizeof(CS_ID *), myflags)))
     return TRUE;
   /* unwarranted chumminess with dynamic_array implementation? */
-  memcpy((char*) charsets->type_names, cs.buffer,
-	 cs.elements * sizeof(my_string *));
-  charsets->type_names[cs.elements] = NullS;
+  memcpy((byte *) *charsets, cs.buffer, cs.elements * sizeof(CS_ID *));
+  (*charsets)[cs.elements] = NULL;
   delete_dynamic(&cs);  
 
   return FALSE;
@@ -164,7 +193,7 @@ static my_bool init_available_charsets(myf myflags)
     charset_initialized=1;
     pthread_mutex_unlock(&THR_LOCK_charset);
   }
-  return error || available_charsets.count == 0;
+  return error || !available_charsets[0];
 }
 
 
@@ -193,7 +222,7 @@ static my_bool fill_array(uchar *array, int sz, struct simpleconfig_buf_st *fb)
 static void get_charset_conf_name(uint cs_number, char *buf)
 {
   strxmov(get_charsets_dir(buf),
-          get_type(&available_charsets, cs_number - 1), ".conf", NullS);
+          name_from_csnum(&available_charsets, cs_number), ".conf", NullS);
 }
 
 
@@ -237,7 +266,7 @@ uint get_charset_number(const char *charset_name)
   if (error)
     return compiled_charset_number(charset_name);
   else
-    return find_type((char*)charset_name, &available_charsets, 1);
+    return num_from_csname((char*)charset_name, &available_charsets, 1);
 }
 
 const char *get_charset_name(uint charset_number)
@@ -247,7 +276,7 @@ const char *get_charset_name(uint charset_number)
   if (error)
     return compiled_charset_name(charset_number);
   else
-    return get_type(&available_charsets, charset_number - 1);
+    return name_from_csnum(&available_charsets, charset_number);
 }
 
 
@@ -452,29 +481,27 @@ char * list_charsets(myf want_flags)
 
   if (want_flags & MY_CONFIG_SETS)
   {
-    uint i;
-    const char *cs_name;
+    CS_ID *c;
     char buf[FN_REFLEN];
     MY_STAT stat;
 
-    for (i = 0; i < available_charsets.count; i++)
+    for (c = available_charsets; *c; ++c)
     {
-      cs_name = get_type(&available_charsets, i);
-      if (charset_in_string(cs_name, &s))
+      if (charset_in_string(c->name, &s))
         continue;
-      get_charset_conf_name(i + 1, buf);
+      get_charset_conf_name(c->number, buf);
       if (!my_stat(buf, &stat, MYF(0)))
         continue;       /* conf file doesn't exist */
-      dynstr_append(&s, cs_name);
+      dynstr_append(&s, c->name);
       dynstr_append(&s, " ");
     }
   }
 
   if (want_flags & MY_INDEX_SETS)
   {
-    uint i;
-    for (i = 0; i < available_charsets.count; i++)
-      charset_append(&s, get_type(&available_charsets, i));
+    CS_ID *c;
+    for (c = available_charsets; *c; ++c)
+      charset_append(&s, c->name);
   }
 
   if (want_flags & MY_LOADED_SETS)