From 483de78fa8ae6fc4882912a762416426f81d053c Mon Sep 17 00:00:00 2001
From: Mryange <yanxuecheng@selectdb.com>
Date: Tue, 11 Mar 2025 15:09:00 +0800
Subject: [PATCH] [fix](function) fix error result when STR_TO_DATE input all
 space (#48872)

before
```
mysql> select STR_TO_DATE ('  ', '%Y-%m-%d %H:%i:%s');
+-----------------------------------------+
| STR_TO_DATE ('  ', '%Y-%m-%d %H:%i:%s') |
+-----------------------------------------+
|                                         |
+-----------------------------------------+
```
now
```
mysql> select STR_TO_DATE ('  ', '%Y-%m-%d %H:%i:%s');
+-----------------------------------------+
| STR_TO_DATE ('  ', '%Y-%m-%d %H:%i:%s') |
+-----------------------------------------+
| NULL                                    |
+-----------------------------------------+
```

Problem Summary:

None

- Test <!-- At least one of them must be included. -->
    - [x] Regression test
    - [x] Unit Test
    - [ ] Manual test (add detailed scripts or steps below)
    - [ ] No need to test or manual test. Explain why:
- [ ] This is a refactor/code format and no logic has been changed.
        - [ ] Previous test can cover this change.
        - [ ] No code files have been changed.
        - [ ] Other reason <!-- Add your reason?  -->

- Behavior changed:
    - [x] No.
    - [ ] Yes. <!-- Explain the behavior change -->

- Does this need documentation?
    - [x] No.
- [ ] Yes. <!-- Add document PR link here. eg:
https://github.com/apache/doris-website/pull/1214 -->

- [ ] Confirm the release note
- [ ] Confirm test cases
- [ ] Confirm document
- [ ] Add branch pick label <!-- Add branch pick label that this PR
should merge into -->
---
 be/src/vec/runtime/vdatetime_value.cpp        |  6 ---
 be/test/vec/runtime/vdatetime_value_test.cpp  | 45 +++++++++++++++++++
 .../data/correctness/test_str_to_date.out     |  3 ++
 .../correctness/test_str_to_date.groovy       |  4 ++
 4 files changed, 52 insertions(+), 6 deletions(-)

diff --git a/be/src/vec/runtime/vdatetime_value.cpp b/be/src/vec/runtime/vdatetime_value.cpp
index 877573bcccb846..7305def114e3d0 100644
--- a/be/src/vec/runtime/vdatetime_value.cpp
+++ b/be/src/vec/runtime/vdatetime_value.cpp
@@ -1247,9 +1247,6 @@ bool VecDateTimeValue::from_date_format_str(const char* format, int format_len,
         while (val < val_end && check_space(*val)) {
             val++;
         }
-        if (val >= val_end) {
-            break;
-        }
         // Check switch
         if (*ptr == '%' && ptr + 1 < end) {
             const char* tmp = nullptr;
@@ -2298,9 +2295,6 @@ bool DateV2Value<T>::from_date_format_str(const char* format, int format_len, co
         while (val < val_end && check_space(*val)) {
             val++;
         }
-        if (val >= val_end) {
-            break;
-        }
         // Check switch
         if (*ptr == '%' && ptr + 1 < end) {
             const char* tmp = nullptr;
diff --git a/be/test/vec/runtime/vdatetime_value_test.cpp b/be/test/vec/runtime/vdatetime_value_test.cpp
index 6c0bfad6b56f24..24d25f80ba7397 100644
--- a/be/test/vec/runtime/vdatetime_value_test.cpp
+++ b/be/test/vec/runtime/vdatetime_value_test.cpp
@@ -632,4 +632,49 @@ TEST(VDateTimeValueTest, date_v2_daynr_test) {
     }
 }
 
+TEST(VDateTimeValueTest, date_v2_from_date_format_str_with_all_space) {
+    auto test_all_space = [](const std::string& format_str) {
+        std::string date_str = "   ";
+        {
+            DateV2Value<DateTimeV2ValueType> date;
+            EXPECT_FALSE(date.from_date_format_str(format_str.data(), format_str.size(),
+                                                   date_str.data(), date_str.size()));
+        }
+
+        {
+            DateV2Value<DateV2ValueType> date;
+            EXPECT_FALSE(date.from_date_format_str(format_str.data(), format_str.size(),
+                                                   date_str.data(), date_str.size()));
+        }
+
+        {
+            VecDateTimeValue date;
+            date._type = TIME_DATE;
+            EXPECT_FALSE(date.from_date_format_str(format_str.data(), format_str.size(),
+                                                   date_str.data(), date_str.size()));
+        }
+
+        {
+            VecDateTimeValue date;
+            date._type = TIME_DATETIME;
+            EXPECT_FALSE(date.from_date_format_str(format_str.data(), format_str.size(),
+                                                   date_str.data(), date_str.size()));
+        }
+    };
+
+    test_all_space("%Y-%m-%d %H:%i:%s.%f");
+    test_all_space("%Y");
+    test_all_space("%Y-%m-%d");
+    test_all_space("%Y-%m-%d %H:%i:%s");
+    test_all_space("%Y-%m-%d %H:%i:%s.%f %p");
+    for (char ch = 'a'; ch <= 'z'; ch++) {
+        std::string fomat_str = "%" + std::string(1, ch);
+        test_all_space(fomat_str);
+    }
+    for (char ch = 'A'; ch <= 'Z'; ch++) {
+        std::string fomat_str = "%" + std::string(1, ch);
+        test_all_space(fomat_str);
+    }
+}
+
 } // namespace doris::vectorized
diff --git a/regression-test/data/correctness/test_str_to_date.out b/regression-test/data/correctness/test_str_to_date.out
index c4326914a7cfbe..9e896c97c7a223 100644
--- a/regression-test/data/correctness/test_str_to_date.out
+++ b/regression-test/data/correctness/test_str_to_date.out
@@ -25,3 +25,6 @@
 -- !short_4 --
 2020-02-01
 
+-- !select_all_space --
+\N
+
diff --git a/regression-test/suites/correctness/test_str_to_date.groovy b/regression-test/suites/correctness/test_str_to_date.groovy
index c2fe22f1f7243d..3335bff7a85476 100644
--- a/regression-test/suites/correctness/test_str_to_date.groovy
+++ b/regression-test/suites/correctness/test_str_to_date.groovy
@@ -52,4 +52,8 @@ suite("test_str_to_date") {
     qt_short_2 " select STR_TO_DATE('2023-12', '%Y-%m') "
     qt_short_3 " select STR_TO_DATE('2023-12', '%Y')"
     qt_short_4 " select STR_TO_DATE('2020%2', '%Y%%%m')"
+
+    qt_select_all_space """
+        SELECT STR_TO_DATE('  ', '%Y-%m-%d %H:%i:%s');
+    """
 }