Revert "*: fix incorrect results about string cmp with collation (pin…

…gcap#5429)" This reverts commit f99b74c.
solotzg · Sep 19, 2022 · 66313b1 · 66313b1
1 parent c21f60b
commit 66313b1
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Showing 3 changed files with 7 additions and 27 deletions.
diff --git a/dbms/src/Columns/ColumnString.cpp b/dbms/src/Columns/ColumnString.cpp
@@ -320,10 +320,9 @@ int ColumnString::compareAtWithCollationImpl(size_t n, size_t m, const IColumn &
 
     return collator.compare(
         reinterpret_cast<const char *>(&chars[offsetAt(n)]),
-        sizeAt(n) - 1, // Skip last zero byte.
+        sizeAt(n),
         reinterpret_cast<const char *>(&rhs.chars[rhs.offsetAt(m)]),
-        rhs.sizeAt(m) - 1 // Skip last zero byte.
-    );
+        rhs.sizeAt(m));
 }
 
 
@@ -342,10 +341,9 @@ struct ColumnString::lessWithCollation
     {
         int res = collator.compare(
             reinterpret_cast<const char *>(&parent.chars[parent.offsetAt(lhs)]),
-            parent.sizeAt(lhs) - 1, // Skip last zero byte.
+            parent.sizeAt(lhs),
             reinterpret_cast<const char *>(&parent.chars[parent.offsetAt(rhs)]),
-            parent.sizeAt(rhs) - 1 // Skip last zero byte.
-        );
+            parent.sizeAt(rhs));
 
         return positive ? (res < 0) : (res > 0);
     }

diff --git a/dbms/src/Columns/ColumnString.h b/dbms/src/Columns/ColumnString.h
@@ -246,8 +246,7 @@ class ColumnString final : public COWPtrHelper<IColumn, ColumnString>
         size_t offset = offsetAt(n);
         if (collator != nullptr)
         {
-            // Skip last zero byte.
-            auto sort_key = collator->sortKey(reinterpret_cast<const char *>(&chars[offset]), string_size - 1, sort_key_container);
+            auto sort_key = collator->sortKey(reinterpret_cast<const char *>(&chars[offset]), string_size, sort_key_container);
             string_size = sort_key.size;
             hash.update(reinterpret_cast<const char *>(&string_size), sizeof(string_size));
             hash.update(sort_key.data, sort_key.size);
@@ -268,8 +267,7 @@ class ColumnString final : public COWPtrHelper<IColumn, ColumnString>
                 size_t string_size = sizeAt(i);
                 size_t offset = offsetAt(i);
 
-                /// Skip last zero byte.
-                auto sort_key = collator->sortKey(reinterpret_cast<const char *>(&chars[offset]), string_size - 1, sort_key_container);
+                auto sort_key = collator->sortKey(reinterpret_cast<const char *>(&chars[offset]), string_size, sort_key_container);
                 string_size = sort_key.size;
                 hash_values[i].update(reinterpret_cast<const char *>(&string_size), sizeof(string_size));
                 hash_values[i].update(sort_key.data, sort_key.size);

diff --git a/tests/tidb-ci/new_collation_fullstack/expr.test b/tests/tidb-ci/new_collation_fullstack/expr.test
@@ -88,20 +88,4 @@ mysql> set session tidb_isolation_read_engines='tiflash'; select /*+ read_from_s
 | min(value) | max(value) | min(value1) | max(value1) |
 +------------+------------+-------------+-------------+
 | abc        | def        | abc         | def         |
-+------------+------------+-------------+-------------+
-
-mysql> insert into test.t values (4, '', 'def\n'), (5, '', 'def    ');
-
-mysql> select /*+ read_from_storage(tiflash[t]) */ hex(max(value1)) from test.t;
-+------------------+
-| hex(max(value1)) |
-+------------------+
-| 6465660A         |
-+------------------+
-
-mysql> select /*+ read_from_storage(tiflash[t]) */ hex(min(value1)) from test.t;
-+------------------+
-| hex(min(value1)) |
-+------------------+
-| 61626320         |
-+------------------+
++------------+------------+-------------+-------------+