MDEV-26785 Hyphens inside the value of uuid datatype

plugin/type_uuid/mysql-test/type_uuid/type_uuid.result

@@ -3120,3 +3120,27 @@ SELECT MIN(a), MAX(a) FROM t1 GROUP BY id;
 MIN(a)	MAX(a)
 00000000-0000-0000-0000-000000000fff	00000000-0000-0000-0000-000000008888
 DROP TABLE t1;
+#
+# MDEV-26785 Hyphens inside the value of uuid datatype
+#
+CREATE TABLE t1 (a UUID);
+INSERT INTO t1 VALUES ('0000000000000000000000000000000'/*31 digits*/);
+ERROR 22007: Incorrect uuid value: '0000000000000000000000000000000' for column `test`.`t1`.`a` at row 1
+INSERT INTO t1 VALUES ('000000000000000000000000000000000'/*33 digits*/);
+ERROR 22007: Incorrect uuid value: '000000000000000000000000000000000' for column `test`.`t1`.`a` at row 1
+INSERT INTO t1 VALUES ('-00000000000000000000000000000000'/*leading hyphen*/);
+ERROR 22007: Incorrect uuid value: '-00000000000000000000000000000000' for column `test`.`t1`.`a` at row 1
+INSERT INTO t1 VALUES ('-00000000000000000000000000000000-'/*trailing hyphen*/);
+ERROR 22007: Incorrect uuid value: '-00000000000000000000000000000000-' for column `test`.`t1`.`a` at row 1
+INSERT INTO t1 VALUES ('00000000000000000000000000000000');
+INSERT INTO t1 VALUES ('0-0000000000000000000000000000011');
+INSERT INTO t1 VALUES ('0--0000000000000000000000000000012');
+INSERT INTO t1 VALUES ('0---0000000000000000000000000000013');
+INSERT INTO t1 VALUES ('0----0000000000000000000000000000014');
+INSERT INTO t1 VALUES ('00-000000000000000000000000000021');
+INSERT INTO t1 VALUES ('00--000000000000000000000000000022');
+INSERT INTO t1 VALUES ('00---000000000000000000000000000023');
+INSERT INTO t1 VALUES ('00----000000000000000000000000000024');
+INSERT INTO t1 VALUES ('5796dac11a1c11--------------ecab4ef859-713e4be4');
+INSERT INTO t1 VALUES ('5796dac11a1c11---------------ecab4ef859-713e4be4');
+DROP TABLE t1;

plugin/type_uuid/mysql-test/type_uuid/type_uuid.test

@@ -1617,3 +1617,32 @@ INSERT INTO t1 VALUES
 (1, '00000000-0000-0000-0000-000000008888');
 SELECT MIN(a), MAX(a) FROM t1 GROUP BY id;
 DROP TABLE t1;
+
+
+--echo #
+--echo # MDEV-26785 Hyphens inside the value of uuid datatype
+--echo #
+
+CREATE TABLE t1 (a UUID);
+--error ER_TRUNCATED_WRONG_VALUE
+INSERT INTO t1 VALUES ('0000000000000000000000000000000'/*31 digits*/);
+--error ER_TRUNCATED_WRONG_VALUE
+INSERT INTO t1 VALUES ('000000000000000000000000000000000'/*33 digits*/);
+--error ER_TRUNCATED_WRONG_VALUE
+INSERT INTO t1 VALUES ('-00000000000000000000000000000000'/*leading hyphen*/);
+--error ER_TRUNCATED_WRONG_VALUE
+INSERT INTO t1 VALUES ('-00000000000000000000000000000000-'/*trailing hyphen*/);
+
+INSERT INTO t1 VALUES ('00000000000000000000000000000000');
+INSERT INTO t1 VALUES ('0-0000000000000000000000000000011');
+INSERT INTO t1 VALUES ('0--0000000000000000000000000000012');
+INSERT INTO t1 VALUES ('0---0000000000000000000000000000013');
+INSERT INTO t1 VALUES ('0----0000000000000000000000000000014');
+INSERT INTO t1 VALUES ('00-000000000000000000000000000021');
+INSERT INTO t1 VALUES ('00--000000000000000000000000000022');
+INSERT INTO t1 VALUES ('00---000000000000000000000000000023');
+INSERT INTO t1 VALUES ('00----000000000000000000000000000024');
+
+INSERT INTO t1 VALUES ('5796dac11a1c11--------------ecab4ef859-713e4be4');
+INSERT INTO t1 VALUES ('5796dac11a1c11---------------ecab4ef859-713e4be4');
+DROP TABLE t1;

plugin/type_uuid/sql_type_uuid.cc

@@ -42,28 +42,61 @@ static bool get_digit(char ch, uint *val)
 }
 
 
-bool UUID::ascii_to_fbt(const char *str, size_t str_length)
+static bool get_digit(uint *val, const char *str, const char *end)
 {
-  if (str_length < 32 || str_length > 3 * binary_length() - 1)
+  if (str >= end)
     return true;
+  return get_digit(*str, val);
+}
+
 
-  uint oidx= 0;
-  for (const char *s= str; s < str + str_length; )
+static size_t skip_hyphens(const char *str, const char *end)
+{
+  const char *str0= str;
+  for ( ; str < end; str++)
   {
-    if (oidx >= binary_length())
-      goto err;
-    if (*s == '-')
-    {
-      if (s == str)
-        goto err;
-      s++;
-      continue;
-    }
-    uint hi, lo;
-    if (get_digit(*s++, &hi) || get_digit(*s++, &lo))
+    if (str[0] != '-')
+      break;
+  }
+  return str - str0;
+}
+
+
+static const char *get_two_digits(char *val, const char *str, const char *end)
+{
+  uint hi, lo;
+  if (get_digit(&hi, str++, end))
+    return NULL;
+  str+= skip_hyphens(str, end);
+  if (get_digit(&lo, str++, end))
+    return NULL;
+  *val= (char) ((hi << 4) + lo);
+  return str;
+}
+
+
+bool UUID::ascii_to_fbt(const char *str, size_t str_length)
+{
+  const char *end= str + str_length;
+  /*
+    The format understood:
+    - Hyphen is not allowed on the first and the last position.
+    - Otherwise, hyphens are allowed on any (odd and even) position,
+      with any amount.
+  */
+  if (str_length < 32)
+    goto err;
+
+  for (uint oidx= 0; oidx < binary_length(); oidx++)
+  {
+    if (!(str= get_two_digits(&m_buffer[oidx], str, end)))
       goto err;
-    m_buffer[oidx++]= (char) ((hi << 4) + lo);
+    // Allow hypheps after two digits, but not after the last digit
+    if (oidx + 1 < binary_length())
+      str+= skip_hyphens(str, end);
   }
+  if (str < end)
+    goto err; // Some input left
   return false;
 err:
   bzero(m_buffer, sizeof(m_buffer));