Bug#20404: SHOW CREATE TABLE fails with Turkish I

  
  Problem: SHOW CREATE TABLE printed garbage in table
  name for tables having TURKISH I
  (i.e. LATIN CAPITABLE LETTER I WITH DOT ABOVE)
  when lower-case-table-name=1.
  
  Reason: In some cases during lower/upper conversion in utf8,
  the result string can be shorter the original string
  (including the above letter). Old implementation of caseup_str()
  and casedn_str() didn't handle the result length properly,
  assuming that length cannot change.
  
  This fix changes the result type of cs->cset->casedn_str()
  and cs->cset->caseup_str() from VOID to UINT, to return
  the result length, as well as put '\0' terminator on a 
  proper place.
  
  Also, my_caseup_str_utf8() and my_casedn_str_utf8() were 
  rewritten not to use strlen() for performance purposes.
  It was done with help of adding of new functions - my_utf8_uni_no_range()
  and my_uni_utf8_no_range() - for null terminated strings.



include/m_ctype.h:
  Changeing return type from void to int for caseup_str() and casedn_str()
mysql-test/r/lowercase_table.result:
  Adding test case
mysql-test/t/lowercase_table.test:
  Adding test case
sql/sql_parse.cc:
  Set table->table.length to result of my_casedn_str().
strings/ctype-bin.c:
  Changeing return type from void to int for caseup_str() and casedn_str()
strings/ctype-mb.c:
  Changeing return type from void to int for caseup_str() and casedn_str()
strings/ctype-simple.c:
  Changeing return type from void to int for caseup_str() and casedn_str()
strings/ctype-ucs2.c:
  Changeing return type from void to int for caseup_str() and casedn_str()
strings/ctype-utf8.c:
  Changeing return type from void to int for caseup_str() and casedn_str().
      Optimization, to get rid of strlen():
      Adding my_utf8_uni_no_range() and my_uni_utf8_no_range() - for null
      terninated strings.

5 files changed, 162 insertions, 26 deletions

diff --git a/strings/ctype-bin.c b/strings/ctype-bin.c
index 0bd5a1fda76..3e8b05580f6 100644
--- a/strings/ctype-bin.c
+++ b/strings/ctype-bin.c
@@ -211,9 +211,10 @@ static int my_strnncollsp_8bit_bin(CHARSET_INFO * cs __attribute__((unused)),
 
 /* This function is used for all conversion functions */
 
-static void my_case_str_bin(CHARSET_INFO *cs __attribute__((unused)),
+static uint my_case_str_bin(CHARSET_INFO *cs __attribute__((unused)),
 			    char *str __attribute__((unused)))
 {
+  return 0;
 }
 
 static uint my_case_bin(CHARSET_INFO *cs __attribute__((unused)),
diff --git a/strings/ctype-mb.c b/strings/ctype-mb.c
index 394111be3bc..3ef245015d7 100644
--- a/strings/ctype-mb.c
+++ b/strings/ctype-mb.c
@@ -21,40 +21,44 @@
 #ifdef USE_MB
 
 
-void my_caseup_str_mb(CHARSET_INFO * cs, char *str)
+uint my_caseup_str_mb(CHARSET_INFO * cs, char *str)
 {
   register uint32 l;
-  register uchar *map=cs->to_upper;
+  register uchar *map= cs->to_upper;
+  char *str_orig= str;
   
   while (*str)
   {
     /* Pointing after the '\0' is safe here. */
-    if ((l=my_ismbchar(cs, str, str + cs->mbmaxlen)))
-      str+=l;
+    if ((l= my_ismbchar(cs, str, str + cs->mbmaxlen)))
+      str+= l;
     else
     { 
-      *str=(char) map[(uchar)*str];
+      *str= (char) map[(uchar)*str];
       str++;
     }
   }
+  return str - str_orig;
 }
 
-void my_casedn_str_mb(CHARSET_INFO * cs, char *str)
+uint my_casedn_str_mb(CHARSET_INFO * cs, char *str)
 {
   register uint32 l;
-  register uchar *map=cs->to_lower;
+  register uchar *map= cs->to_lower;
+  char *str_orig= str;
   
   while (*str)
   {
     /* Pointing after the '\0' is safe here. */
-    if ((l=my_ismbchar(cs, str, str + cs->mbmaxlen)))
-      str+=l;
+    if ((l= my_ismbchar(cs, str, str + cs->mbmaxlen)))
+      str+= l;
     else
     {
-      *str=(char) map[(uchar)*str];
+      *str= (char) map[(uchar)*str];
       str++;
     }
   }
+  return str - str_orig;
 }
 
 uint my_caseup_mb(CHARSET_INFO * cs, char *src, uint srclen,
diff --git a/strings/ctype-simple.c b/strings/ctype-simple.c
index e40a1948dcf..7484f3c0d92 100644
--- a/strings/ctype-simple.c
+++ b/strings/ctype-simple.c
@@ -188,20 +188,26 @@ int my_strnncollsp_simple(CHARSET_INFO * cs, const uchar *a, uint a_length,
 }
 
 
-void my_caseup_str_8bit(CHARSET_INFO * cs,char *str)
+uint my_caseup_str_8bit(CHARSET_INFO * cs,char *str)
 {
-  register uchar *map=cs->to_upper;
-  while ((*str = (char) map[(uchar) *str]) != 0)
+  register uchar *map= cs->to_upper;
+  char *str_orig= str;
+  while ((*str= (char) map[(uchar) *str]) != 0)
     str++;
+  return str - str_orig;
 }
 
-void my_casedn_str_8bit(CHARSET_INFO * cs,char *str)
+
+uint my_casedn_str_8bit(CHARSET_INFO * cs,char *str)
 {
-  register uchar *map=cs->to_lower;
-  while ((*str = (char) map[(uchar)*str]) != 0)
+  register uchar *map= cs->to_lower;
+  char *str_orig= str;
+  while ((*str= (char) map[(uchar) *str]) != 0)
     str++;
+  return str - str_orig;
 }
 
+
 uint my_caseup_8bit(CHARSET_INFO * cs, char *src, uint srclen,
                     char *dst __attribute__((unused)),
                     uint dstlen __attribute__((unused)))
diff --git a/strings/ctype-ucs2.c b/strings/ctype-ucs2.c
index 4a60220f73e..3c69a314b45 100644
--- a/strings/ctype-ucs2.c
+++ b/strings/ctype-ucs2.c
@@ -159,13 +159,13 @@ static void my_hash_sort_ucs2(CHARSET_INFO *cs, const uchar *s, uint slen,
 }
 
 
-static void my_caseup_str_ucs2(CHARSET_INFO * cs  __attribute__((unused)), 
+static uint my_caseup_str_ucs2(CHARSET_INFO * cs  __attribute__((unused)), 
 			       char * s __attribute__((unused)))
 {
+  return 0;
 }
 
 
-
 static uint my_casedn_ucs2(CHARSET_INFO *cs, char *src, uint srclen,
                            char *dst __attribute__((unused)),
                            uint dstlen __attribute__((unused)))
@@ -188,9 +188,11 @@ static uint my_casedn_ucs2(CHARSET_INFO *cs, char *src, uint srclen,
   return srclen;
 }
 
-static void my_casedn_str_ucs2(CHARSET_INFO *cs __attribute__((unused)), 
+
+static uint my_casedn_str_ucs2(CHARSET_INFO *cs __attribute__((unused)), 
 			       char * s __attribute__((unused)))
 {
+  return 0;
 }
 
 
diff --git a/strings/ctype-utf8.c b/strings/ctype-utf8.c
index ae2c04fb068..a21fe4961ec 100644
--- a/strings/ctype-utf8.c
+++ b/strings/ctype-utf8.c
@@ -2045,6 +2045,52 @@ static int my_utf8_uni(CHARSET_INFO *cs __attribute__((unused)),
   return MY_CS_ILSEQ;
 }
 
+
+/*
+  The same as above, but without range check
+  for example, for a null-terminated string
+*/
+static int my_utf8_uni_no_range(CHARSET_INFO *cs __attribute__((unused)),
+                                my_wc_t * pwc, const uchar *s)
+{
+  unsigned char c;
+
+  c= s[0];
+  if (c < 0x80)
+  {
+    *pwc = c;
+    return 1;
+  }
+
+  if (c < 0xc2)
+    return MY_CS_ILSEQ;
+
+  if (c < 0xe0)
+  {
+    if (!((s[1] ^ 0x80) < 0x40))
+      return MY_CS_ILSEQ;
+
+    *pwc = ((my_wc_t) (c & 0x1f) << 6) | (my_wc_t) (s[1] ^ 0x80);
+    return 2;
+  }
+  
+  if (c < 0xf0)
+  {
+    if (!((s[1] ^ 0x80) < 0x40 &&
+          (s[2] ^ 0x80) < 0x40 &&
+          (c >= 0xe1 || s[1] >= 0xa0)))
+      return MY_CS_ILSEQ;
+
+    *pwc= ((my_wc_t) (c & 0x0f) << 12)   |
+          ((my_wc_t) (s[1] ^ 0x80) << 6) |
+           (my_wc_t) (s[2] ^ 0x80);
+
+    return 3;
+  }
+  return MY_CS_ILSEQ;
+}
+
+
 static int my_uni_utf8 (CHARSET_INFO *cs __attribute__((unused)) ,
                  my_wc_t wc, uchar *r, uchar *e)
 {
@@ -2091,6 +2137,34 @@ static int my_uni_utf8 (CHARSET_INFO *cs __attribute__((unused)) ,
 }
 
 
+/*
+  The same as above, but without range check.
+*/
+static int my_uni_utf8_no_range(CHARSET_INFO *cs __attribute__((unused)),
+                                my_wc_t wc, uchar *r)
+{
+  int count;
+
+  if (wc < 0x80)
+    count= 1;
+  else if (wc < 0x800)
+    count= 2;
+  else if (wc < 0x10000)
+    count= 3;
+  else
+    return MY_CS_ILUNI;
+
+  switch (count)
+  {
+    /* Fall through all cases!!! */
+    case 3: r[2]= (uchar) (0x80 | (wc & 0x3f)); wc= wc >> 6; wc |= 0x800;
+    case 2: r[1]= (uchar) (0x80 | (wc & 0x3f)); wc= wc >> 6; wc |= 0xc0;
+    case 1: r[0]= (uchar) wc;
+  }
+  return count;
+}
+
+
 static uint my_caseup_utf8(CHARSET_INFO *cs, char *src, uint srclen,
                                              char *dst, uint dstlen)
 {
@@ -2141,10 +2215,26 @@ static void my_hash_sort_utf8(CHARSET_INFO *cs, const uchar *s, uint slen,
 }
 
 
-static void my_caseup_str_utf8(CHARSET_INFO * cs, char * s)
+static uint my_caseup_str_utf8(CHARSET_INFO *cs, char *src)
 {
-  uint len= (uint) strlen(s);
-  my_caseup_utf8(cs, s, len, s, len);
+  my_wc_t wc;
+  int srcres, dstres;
+  char *dst= src, *dst0= src;
+  MY_UNICASE_INFO **uni_plane= cs->caseinfo;
+  DBUG_ASSERT(cs->caseup_multiply == 1);
+
+  while (*src &&
+         (srcres= my_utf8_uni_no_range(cs, &wc, (uchar *) src)) > 0)
+  {
+    int plane= (wc>>8) & 0xFF;
+    wc= uni_plane[plane] ? uni_plane[plane][wc & 0xFF].toupper : wc;
+    if ((dstres= my_uni_utf8_no_range(cs, wc, (uchar*) dst)) <= 0)
+      break;
+    src+= srcres;
+    dst+= dstres;
+  }
+  *dst= '\0';
+  return (uint) (dst - dst0);
 }
 
 
@@ -2170,10 +2260,43 @@ static uint my_casedn_utf8(CHARSET_INFO *cs, char *src, uint srclen,
   return (uint) (dst - dst0);
 }
 
-static void my_casedn_str_utf8(CHARSET_INFO *cs, char * s)
+
+static uint my_casedn_str_utf8(CHARSET_INFO *cs, char *src)
 {
-  uint len= (uint) strlen(s);
-  my_casedn_utf8(cs, s, len, s, len);
+  my_wc_t wc;
+  int srcres, dstres;
+  char *dst= src, *dst0= src;
+  MY_UNICASE_INFO **uni_plane= cs->caseinfo;
+  DBUG_ASSERT(cs->casedn_multiply == 1);
+
+  while (*src &&
+         (srcres= my_utf8_uni_no_range(cs, &wc, (uchar *) src)) > 0)
+  {
+    int plane= (wc>>8) & 0xFF;
+    wc= uni_plane[plane] ? uni_plane[plane][wc & 0xFF].tolower : wc;
+    if ((dstres= my_uni_utf8_no_range(cs, wc, (uchar*) dst)) <= 0)
+      break;
+    src+= srcres;
+    dst+= dstres;
+  }
+
+  /*
+   In rare cases lower string can be shorter than
+   the original string, for example:
+
+   "U+0130 LATIN CAPITAL LETTER I WITH DOT ABOVE"
+   (which is 0xC4B0 in utf8, i.e. two bytes)
+
+   is converted into
+
+   "U+0069 LATIN SMALL LETTER I"
+   (which is 0x69 in utf8, i.e. one byte)
+
+   So, we need to put '\0' terminator after converting.
+  */
+
+  *dst= '\0';
+  return (uint) (dst - dst0);
 }