MDEV-8334: Rename utf8 to utf8mb3

This patch changes the main name of 3 byte character set from utf8 to
utf8mb3. New old_mode UTF8_IS_UTF8MB3 is added and set TRUE by default,
so that utf8 would mean utf8mb3. If not set, utf8 would mean utf8mb4.

2 files changed, 23 insertions, 26 deletions

diff --git a/mysys/charset.c b/mysys/charset.c
index 32cfeb56e2d..c786488d09f 100644
--- a/mysys/charset.c
+++ b/mysys/charset.c
@@ -722,25 +722,26 @@ void free_charsets(void)
 
 
 static const char*
-get_collation_name_alias(const char *name, char *buf, size_t bufsize)
+get_collation_name_alias(const char *name, char *buf, size_t bufsize, myf flags)
 {
-  if (!strncasecmp(name, "utf8mb3_", 8))
+  if (!strncasecmp(name, "utf8_", 5))
   {
-    my_snprintf(buf, bufsize, "utf8_%s", name + 8);
+    my_snprintf(buf, bufsize, "utf8mb%c_%s",
+       flags & MY_UTF8_IS_UTF8MB3 ? '3' : '4', name + 5);
     return buf;
   }
   return NULL;
 }
 
 
-uint get_collation_number(const char *name)
+uint get_collation_number(const char *name, myf flags)
 {
   uint id;
   char alias[64];
   my_pthread_once(&charsets_initialized, init_available_charsets);
   if ((id= get_collation_number_internal(name)))
     return id;
-  if ((name= get_collation_name_alias(name, alias, sizeof(alias))))
+  if ((name= get_collation_name_alias(name, alias, sizeof(alias),flags)))
     return get_collation_number_internal(name);
   return 0;
 }
@@ -763,22 +764,16 @@ get_charset_number_internal(const char *charset_name, uint cs_flags)
 }
 
 
-static const char*
-get_charset_name_alias(const char *name)
-{
-  if (!my_strcasecmp(&my_charset_latin1, name, "utf8mb3"))
-    return "utf8";
-  return NULL;
-}
-
-
-uint get_charset_number(const char *charset_name, uint cs_flags)
+uint get_charset_number(const char *charset_name, uint cs_flags, myf flags)
 {
   uint id;
+  const char *new_charset_name= flags & MY_UTF8_IS_UTF8MB3 ? "utf8mb3" :
+                                                             "utf8mb4";
   my_pthread_once(&charsets_initialized, init_available_charsets);
   if ((id= get_charset_number_internal(charset_name, cs_flags)))
     return id;
-  if ((charset_name= get_charset_name_alias(charset_name)))
+  if ((charset_name= !my_strcasecmp(&my_charset_latin1, charset_name, "utf8") ?
+                      new_charset_name : NULL))
     return get_charset_number_internal(charset_name, cs_flags);
   return 0;
 }
@@ -809,7 +804,7 @@ static CHARSET_INFO *inheritance_source_by_id(CHARSET_INFO *cs, uint refid)
 }
 
 
-static CHARSET_INFO *find_collation_data_inheritance_source(CHARSET_INFO *cs)
+static CHARSET_INFO *find_collation_data_inheritance_source(CHARSET_INFO *cs, myf flags)
 {
   const char *beg, *end;
   if (cs->tailoring &&
@@ -820,7 +815,7 @@ static CHARSET_INFO *find_collation_data_inheritance_source(CHARSET_INFO *cs)
     char name[MY_CS_NAME_SIZE + 1];
     memcpy(name, beg, end - beg);
     name[end - beg]= '\0';
-    return inheritance_source_by_id(cs, get_collation_number(name));
+    return inheritance_source_by_id(cs, get_collation_number(name,MYF(flags)));
   }
   return NULL;
 }
@@ -875,7 +870,7 @@ get_internal_charset(MY_CHARSET_LOADER *loader, uint cs_number, myf flags)
         }
         if (!simple_8bit_collation_data_is_full(cs))
         {
-          CHARSET_INFO *refcl= find_collation_data_inheritance_source(cs);
+          CHARSET_INFO *refcl= find_collation_data_inheritance_source(cs, flags);
           if (refcl)
             inherit_collation_data(cs, refcl);
         }
@@ -944,7 +939,7 @@ my_collation_get_by_name(MY_CHARSET_LOADER *loader,
   CHARSET_INFO *cs;
   my_pthread_once(&charsets_initialized, init_available_charsets);
 
-  cs_number= get_collation_number(name);
+  cs_number= get_collation_number(name,flags);
   my_charset_loader_init_mysys(loader);
   cs= cs_number ? get_internal_charset(loader, cs_number, flags) : NULL;
 
@@ -986,7 +981,7 @@ my_charset_get_by_name(MY_CHARSET_LOADER *loader,
 
   my_pthread_once(&charsets_initialized, init_available_charsets);
 
-  cs_number= get_charset_number(cs_name, cs_flags);
+  cs_number= get_charset_number(cs_name, cs_flags, flags);
   cs= cs_number ? get_internal_charset(loader, cs_number, flags) : NULL;
 
   if (!cs && (flags & MY_WME))
@@ -1027,9 +1022,10 @@ get_charset_by_csname(const char *cs_name, uint cs_flags, myf flags)
 
 my_bool resolve_charset(const char *cs_name,
                         CHARSET_INFO *default_cs,
-                        CHARSET_INFO **cs)
+                        CHARSET_INFO **cs,
+                        myf flags)
 {
-  *cs= get_charset_by_csname(cs_name, MY_CS_PRIMARY, MYF(0));
+  *cs= get_charset_by_csname(cs_name, MY_CS_PRIMARY, flags);
 
   if (*cs == NULL)
   {
@@ -1059,9 +1055,10 @@ my_bool resolve_charset(const char *cs_name,
 
 my_bool resolve_collation(const char *cl_name,
                           CHARSET_INFO *default_cl,
-                          CHARSET_INFO **cl)
+                          CHARSET_INFO **cl,
+                          myf my_flags)
 {
-  *cl= get_charset_by_name(cl_name, MYF(0));
+  *cl= get_charset_by_name(cl_name, my_flags);
 
   if (*cl == NULL)
   {
diff --git a/mysys/test_charset.c b/mysys/test_charset.c
index f8392a9d3a9..133a5ca1cbf 100644
--- a/mysys/test_charset.c
+++ b/mysys/test_charset.c
@@ -70,7 +70,7 @@ int main(int argc, char **argv) {
   if (argc > argcnt)
     charsets_dir = argv[argcnt++];
 
-  if (!(cs= get_charset_by_name(the_set, MYF(MY_WME))))
+  if (!(cs= get_charset_by_name(the_set, MYF(MY_UTF8_IS_UTF8MB3 | MY_WME))))
     return 1;
 
   puts("CHARSET INFO:");