expression: Report error when empty pattern in regexp related function (

#53230) close #53221
pingcap · May 14, 2024 · 4b91fee · 4b91fee
1 parent 78549f3
commit 4b91fee
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Showing 3 changed files with 36 additions and 5 deletions.
diff --git a/pkg/executor/test/issuetest/BUILD.bazel b/pkg/executor/test/issuetest/BUILD.bazel
@@ -8,7 +8,7 @@ go_test(
         "main_test.go",
     ],
     flaky = True,
-    shard_count = 20,
+    shard_count = 21,
     deps = [
         "//pkg/autoid_service",
         "//pkg/config",

diff --git a/pkg/executor/test/issuetest/executor_issue_test.go b/pkg/executor/test/issuetest/executor_issue_test.go
@@ -676,3 +676,27 @@ func TestIssue52978(t *testing.T) {
 	tk.MustQuery("select min(truncate(cast(-26340 as double), ref_11.a)) as c3 from t as ref_11;").Check(testkit.Rows("-26340"))
 	tk.MustExec("drop table if exists t")
 }
+
+func TestIssue53221(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t (a varchar(20))")
+	tk.MustExec("insert into t values ('')")
+	tk.MustExec("insert into t values ('')")
+	err := tk.QueryToErr("select regexp_like('hello', t.a) from test.t")
+	require.ErrorContains(t, err, "Empty pattern is invalid")
+
+	err = tk.QueryToErr("select regexp_instr('hello', t.a) from test.t")
+	require.ErrorContains(t, err, "Empty pattern is invalid")
+
+	err = tk.QueryToErr("select regexp_substr('hello', t.a) from test.t")
+	require.ErrorContains(t, err, "Empty pattern is invalid")
+
+	err = tk.QueryToErr("select regexp_replace('hello', t.a, 'd') from test.t")
+	require.ErrorContains(t, err, "Empty pattern is invalid")
+
+	tk.MustExec("drop table if exists t")
+}
diff --git a/pkg/expression/builtin_regexp.go b/pkg/expression/builtin_regexp.go
@@ -96,6 +96,10 @@ func (re *regexpBaseFuncSig) canMemorizeRegexp(matchTypeIdx int) bool {
 
 // buildRegexp builds a new `*regexp.Regexp` from the pattern and matchType
 func (re *regexpBaseFuncSig) buildRegexp(pattern string, matchType string) (reg *regexp.Regexp, err error) {
+	if len(pattern) == 0 {
+		return nil, ErrRegexp.GenWithStackByArgs(emptyPatternErr)
+	}
+
 	matchType, err = getRegexpMatchType(matchType, re.collation)
 	if err != nil {
 		return nil, err
@@ -314,7 +318,8 @@ func (re *builtinRegexpLikeFuncSig) vecEvalInt(ctx EvalContext, input *chunk.Chu
 
 		if !memorized {
 			matchType := params[2].getStringVal(i)
-			reg, err = re.buildRegexp(params[1].getStringVal(i), matchType)
+			pattern := params[1].getStringVal(i)
+			reg, err = re.buildRegexp(pattern, matchType)
 			if err != nil {
 				return err
 			}
@@ -583,8 +588,8 @@ func (re *builtinRegexpSubstrFuncSig) vecEvalString(ctx EvalContext, input *chun
 
 		if !memorized {
 			// Get pattern and match type and then generate regexp
-			pattern := params[1].getStringVal(i)
 			matchType := params[4].getStringVal(i)
+			pattern := params[1].getStringVal(i)
 			if reg, err = re.buildRegexp(pattern, matchType); err != nil {
 				return err
 			}
@@ -915,7 +920,8 @@ func (re *builtinRegexpInStrFuncSig) vecEvalInt(ctx EvalContext, input *chunk.Ch
 		// Get match type and generate regexp
 		if !memorized {
 			matchType := params[5].getStringVal(i)
-			reg, err = re.buildRegexp(params[1].getStringVal(i), matchType)
+			pattern := params[1].getStringVal(i)
+			reg, err = re.buildRegexp(pattern, matchType)
 			if err != nil {
 				return err
 			}
@@ -1401,7 +1407,8 @@ func (re *builtinRegexpReplaceFuncSig) vecEvalString(ctx EvalContext, input *chu
 		// Get match type and generate regexp
 		if !memorized {
 			matchType := params[5].getStringVal(i)
-			reg, err = re.buildRegexp(params[1].getStringVal(i), matchType)
+			pattern := params[1].getStringVal(i)
+			reg, err = re.buildRegexp(pattern, matchType)
 			if err != nil {
 				return err
 			}