Fix <SelectInput> shows gap in border when using no label with outlined variant

Author: fzaninotto

packages/ra-ui-materialui/src/input/SelectInput.stories.tsx

@@ -101,6 +101,45 @@ export const Disabled = () => (
     </Wrapper>
 );
 
+export const Variant = ({ hideLabel }) => (
+    <Wrapper>
+        <SelectInput
+            source="gender"
+            choices={[
+                { id: 'M', name: 'Male ' },
+                { id: 'F', name: 'Female' },
+            ]}
+            label={hideLabel ? false : 'default'}
+        />
+        <SelectInput
+            source="gender"
+            choices={[
+                { id: 'M', name: 'Male ' },
+                { id: 'F', name: 'Female' },
+            ]}
+            label={hideLabel ? false : 'outlined'}
+            variant="outlined"
+        />
+        <SelectInput
+            source="gender"
+            choices={[
+                { id: 'M', name: 'Male ' },
+                { id: 'F', name: 'Female' },
+            ]}
+            label={hideLabel ? false : 'standard'}
+            variant="standard"
+        />
+    </Wrapper>
+);
+Variant.args = {
+    hideLabel: false,
+};
+Variant.argTypes = {
+    hideLabel: {
+        type: 'boolean',
+    },
+};
+
 export const ReadOnly = () => (
     <Wrapper>
         <SelectInput

packages/ra-ui-materialui/src/input/SelectInput.tsx

@@ -306,15 +306,14 @@ export const SelectInput = (props: SelectInputProps) => {
                 onChange={handleChangeWithCreateSupport}
                 select
                 label={
-                    label !== '' &&
-                    label !== false && (
+                    label !== '' && label !== false ? (
                         <FieldTitle
                             label={label}
                             source={source}
                             resource={resourceProp}
                             isRequired={isRequired}
                         />
-                    )
+                    ) : null
                 }
                 clearAlwaysVisible
                 error={!!fetchError || invalid}