fix bug of weight_string

deps/oblib/src/lib/charset/ob_ctype_gb18030_os.cc

@@ -19475,7 +19475,7 @@ static size_t ob_strnxfrm_gb18030(const ObCharsetInfo *cs, uchar *dst,
       ++src;
     }
   }
-  return ob_strxfrm_pad(cs, ds, dst, de, nweights, flags);
+  return ob_strxfrm_pad_desc_and_reverse(cs, ds, dst, de, nweights, flags, 0);
 }
 
 size_t ob_varlen_encoding_gb18030_for_memcmp(const struct ObCharsetInfo* cs,		

src/sql/engine/expr/ob_expr_weight_string.cpp

@@ -21,6 +21,8 @@
 #include "lib/oblog/ob_log.h"
 #include "sql/engine/expr/ob_datum_cast.h"
 #include "ob_expr_util.h"
+#include "sql/engine/ob_exec_context.h"
+#include "sql/session/ob_sql_session_info.h"
 
 using namespace oceanbase::common;
 
@@ -46,11 +48,6 @@ int ObExprWeightString::calc_result_typeN(ObExprResType &type,
   if (NOT_ROW_DIMENSION != row_dimension_ || ObMaxType == types_stack[0].get_type()) {
     ret = OB_ERR_INVALID_TYPE_FOR_OP;
   } else {
-    if (types_stack[0].get_type() > ObUNumberType && types_stack[0].get_type() != ObBitType) {
-      // 输入不是数字类型时
-      type_ctx.set_cast_mode(type_ctx.get_cast_mode() | CM_NULL_ON_WARN);
-      types_stack[0].set_calc_type(ObVarcharType);
-    }
     uint64_t max_length = OB_MAX_VARBINARY_LENGTH; // The maximum length of the result of WEIGHT_STRING()
     uint64_t result_length = types_stack[1].get_param().get_int();
     uint64_t nweight = types_stack[2].get_param().get_int();
@@ -58,8 +55,17 @@ int ObExprWeightString::calc_result_typeN(ObExprResType &type,
     ObCollationLevel coll_level = CS_LEVEL_INVALID;
     if (as_binary) {
       coll_level = CS_LEVEL_IMPLICIT;
+      type_ctx.set_cast_mode(type_ctx.get_cast_mode() | CM_NULL_ON_WARN);
+      types_stack[0].set_calc_type(ObVarcharType);
     } else {
       coll_level = types_stack[0].get_collation_level();
+      if (types_stack[0].get_type() > ObUNumberType &&
+          types_stack[0].get_type() != ObBitType &&
+          types_stack[0].get_type() != ObYearType) {
+        // 输入不是数字类型时
+        type_ctx.set_cast_mode(type_ctx.get_cast_mode() | CM_NULL_ON_WARN);
+        types_stack[0].set_calc_type(ObVarcharType);
+      }
     }
     ObCollationType collation_type = types_stack[0].get_collation_type();
     const ObCharsetInfo *cs = ObCharset::get_charset(collation_type); 
@@ -106,18 +112,32 @@ int ObExprWeightString::eval_weight_string(const ObExpr &expr, ObEvalCtx &ctx, O
                                 KP(nweights_arg),
                                 KP(flags_arg),
                                 KP(as_binary_arg));
-  } else if (arg->is_null() || expr.args_[0]->datum_meta_.type_ <= ObUNumberType || expr.args_[0]->datum_meta_.type_ == ObBitType) {
-    // The input string is NULL or numeric
-    res_datum.set_null();
-  } else if (arg->get_string().length() == 0 && arg->get_string().ptr() == nullptr) {
-    res_datum.set_string(nullptr,0);
   } else {
     const ObString str = arg->get_string();
     uint64_t result_length = result_length_arg->get_int();
     uint64_t nweights = nweights_arg->get_int();
     uint64_t flags = flags_arg->get_int();
     bool as_binary = as_binary_arg->get_int();
-
+    int64_t max_allowed_packet = 0;
+    ObSQLSessionInfo *session = ctx.exec_ctx_.get_my_session();
+    if (arg->is_null()) {
+      // The input string is NULL
+      res_datum.set_null();
+    } else if (!as_binary && (expr.args_[0]->datum_meta_.type_ <= ObUNumberType ||
+                              expr.args_[0]->datum_meta_.type_ == ObBitType ||
+                              expr.args_[0]->datum_meta_.type_ == ObYearType)) {
+      res_datum.set_null();
+    } else if (arg->get_string().empty() && nweights == 0) {
+      res_datum.set_string(nullptr,0);
+    } else {
+      if (OB_FAIL(session->get_max_allowed_packet(max_allowed_packet))) {
+        if (OB_ENTRY_NOT_EXIST == ret) {
+          ret = OB_SUCCESS;
+          max_allowed_packet = OB_MAX_VARCHAR_LENGTH;
+        } else {
+          LOG_WARN("Failed to get max allow packet size", K(ret));
+        }
+      }
       // Get the character set and collation information of the input string
       ObCollationType collation_type = CS_TYPE_INVALID;
       if (as_binary) {
@@ -135,6 +155,9 @@ int ObExprWeightString::eval_weight_string(const ObExpr &expr, ObEvalCtx &ctx, O
       } else {
         tmp_length = cs->coll->strnxfrmlen(cs, cs->mbmaxlen*MAX(str.length() , nweights));
       }
+      if (tmp_length >= max_allowed_packet) {
+        res_datum.set_null();
+      } else {
         int used_nweights = nweights;
         size_t input_length = str.length();
         if (used_nweights) {
@@ -160,6 +183,8 @@ int ObExprWeightString::eval_weight_string(const ObExpr &expr, ObEvalCtx &ctx, O
           res_datum.set_string(out_buf,frm_length);
         }
       }
+    }
+  }
   return ret;
 }