Merge pull request #1425 from Altinity/backports/releases/25.3.14/82900

25.3.14 Stable backport of ClickHouse#82900: `trim` - return a const value for all-const inputs (Bug 78796)

Author: zvonand

src/Functions/trim.cpp

@@ -26,6 +26,7 @@ class FunctionTrim : public IFunction
     String getName() const override { return name; }
     bool isVariadic() const override { return true; }
     bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return true; }
+    bool useDefaultImplementationForConstants() const override { return true; }
     size_t getNumberOfArguments() const override { return 0; }
 
     DataTypePtr getReturnTypeImpl(const ColumnsWithTypeAndName & arguments) const override
@@ -48,9 +49,16 @@ class FunctionTrim : public IFunction
         std::optional<SearchSymbols> custom_trim_characters;
         if (arguments.size() == 2 && input_rows_count > 0)
         {
-            const ColumnConst * col_trim_characters_const = checkAndGetColumnConst<ColumnString>(arguments[1].column.get());
-            const String & trim_characters_string = col_trim_characters_const->getDataAt(0).toString();
-            custom_trim_characters = std::make_optional<SearchSymbols>(trim_characters_string);
+            if (const ColumnString * col_trim_characters = checkAndGetColumn<ColumnString>(arguments[1].column.get()))
+            {
+                const String & trim_characters_string = col_trim_characters->getDataAt(0).toString();
+                custom_trim_characters = std::make_optional<SearchSymbols>(trim_characters_string);
+            }
+            else if (const ColumnConst * col_trim_characters_const = checkAndGetColumnConst<ColumnString>(arguments[1].column.get()))
+            {
+                const String & trim_characters_string = col_trim_characters_const->getDataAt(0).toString();
+                custom_trim_characters = std::make_optional<SearchSymbols>(trim_characters_string);
+            }
         }
 
         ColumnPtr col_input_full;

tests/queries/0_stateless/03315_trim_two_args.reference

@@ -22,3 +22,4 @@ Negative tests
 Special tests
 abc
 b
+1

tests/queries/0_stateless/03315_trim_two_args.sql

@@ -106,3 +106,6 @@ INSERT INTO tab VALUES ('abc');
 SELECT trim(trailing char(0) from col) FROM tab;
 SELECT trim(both 'ac' from col) FROM tab;
 DROP TABLE tab;
+
+-- Bug 78796
+SELECT isConstant(trimBoth(''));