[fix](function) fix error result when STR_TO_DATE input all space (#4… (#48920)

…8872)
https://github.com/apache/doris/pull/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 -->

### What problem does this PR solve?

Issue Number: close #xxx

Related PR: #xxx

Problem Summary:

### Release note

None

### Check List (For Author)

- Test <!-- At least one of them must be included. -->
    - [ ] Regression test
    - [ ] 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:
    - [ ] No.
    - [ ] Yes. <!-- Explain the behavior change -->

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

### Check List (For Reviewer who merge this PR)

- [ ] 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

@@ -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;

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

regression-test/data/correctness/test_str_to_date.out

@@ -25,3 +25,6 @@
 -- !short_4 --
 2020-02-01
 
+-- !select_all_space --
+\N
+

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');
+    """
 }