Critical fixes after review:

- mutex was unlocked before the end of the critical sesion,
- Portability issue: It's better to use (*alloc)(x) instead of alloc(x),
  if alloc is a function passed as an argument.
- Use {} around if() block, to avoid possible problems with some Windows compilers.

mysys/charset.c

@@ -469,7 +469,6 @@ static CHARSET_INFO *get_internal_charset(uint cs_number, myf flags)
     }
     cs= (cs->state & MY_CS_AVAILABLE) ? cs : NULL;
   }
-  pthread_mutex_unlock(&THR_LOCK_charset);
   if (cs && !(cs->state & MY_CS_READY))
   {
     if ((cs->cset->init && cs->cset->init(cs, cs_alloc)) ||
@@ -478,6 +477,7 @@ static CHARSET_INFO *get_internal_charset(uint cs_number, myf flags)
     else
       cs->state|= MY_CS_READY;
   }
+  pthread_mutex_unlock(&THR_LOCK_charset);
   return cs;
 }
 

sql/sql_string.cc

@@ -370,7 +370,7 @@ bool String::copy(const char *str, uint32 arg_length,
 
 bool String::set_ascii(const char *str, uint32 arg_length)
 {
-  if (!(str_charset->mbminlen > 1))
+  if (str_charset->mbminlen == 1)
   {
     set(str, arg_length, str_charset);
     return 0;

strings/ctype-uca.c

@@ -7549,8 +7549,8 @@ typedef struct my_coll_rule_item_st
   USAGE
     
   RETURN VALUES
-    0 - OK
-    1 - ERROR, e.g. too many items.
+    A positive number means the number of rules loaded.
+   -1 means ERROR, e.g. too many items, syntax error, etc.
 */
 
 static int my_coll_rule_parse(MY_COLL_RULE *rule, size_t mitems,
@@ -7706,11 +7706,11 @@ static my_bool create_tailoring(CHARSET_INFO *cs, void *(*alloc)(uint))
     return 1;
   }
   
-  if (!(newweights= (uint16**) alloc(256*sizeof(uint16*))))
+  if (!(newweights= (uint16**) (*alloc)(256*sizeof(uint16*))))
     return 1;
   bzero(newweights, 256*sizeof(uint16*));
   
-  if (!(newlengths= (uchar*) alloc(256)))
+  if (!(newlengths= (uchar*) (*alloc)(256)))
     return 1;
   
   memcpy(newlengths, deflengths, 256);
@@ -7747,7 +7747,7 @@ static my_bool create_tailoring(CHARSET_INFO *cs, void *(*alloc)(uint))
       /* Alloc new page and copy the default UCA weights */
       uint size= 256*newlengths[pagec]*sizeof(uint16);
       
-      if (!(newweights[pagec]= (uint16*) alloc(size)))
+      if (!(newweights[pagec]= (uint16*) (*alloc)(size)))
         return 1;
       bzero((void*) newweights[pagec], size);
       
@@ -7774,8 +7774,10 @@ static my_bool create_tailoring(CHARSET_INFO *cs, void *(*alloc)(uint))
   
   /* Copy non-overwritten pages from the default UCA weights */
   for (i= 0; i < 256 ; i++)
+  {
     if (!newweights[i])
       newweights[i]= defweights[i];
+  }
   
   cs->sort_order= newlengths;
   cs->sort_order_big= newweights;
@@ -7785,7 +7787,7 @@ static my_bool create_tailoring(CHARSET_INFO *cs, void *(*alloc)(uint))
   if (ncontractions)
   {
     uint size= 0x40*0x40*sizeof(uint16); /* 8K, for basic latin letter only */
-    if (!(cs->contractions= (uint16*) alloc(size)))
+    if (!(cs->contractions= (uint16*) (*alloc)(size)))
         return 1;
     bzero((void*)cs->contractions, size);
     for (i=0; i < rc; i++)