xml: fail for non-string values (#11959)

* fix(xml): coerce boolean values to string with a warning

Fixes #7171

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* test(xml): add integration tests for boolean value handling

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* changelog: add fragment for PR 11959

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* adjustments from review

* test(xml): update boolean-value integration tests to expect failure

Now that xml fails on non-string values, replace the old success-path
tests with failure assertions and add a positive test for quoted strings.
Remove the no-longer-needed result XML fixtures.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* adjustments from review

* fix(xml): correct boolean test assertions to match actual error message format

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

plugins/modules/xml.py

@@ -695,6 +695,16 @@ def set_target_inner(module, tree, xpath, namespaces, attribute, value):
             msg=f"Xpath {xpath} does not reference a node! tree is {etree.tostring(tree, pretty_print=True)}"
         )
 
+    if not isinstance(value, str):
+        target = f"attribute '{attribute}' at xpath '{xpath}'" if attribute else f"element text at xpath '{xpath}'"
+        module.fail_json(
+            msg=(
+                f"A non-string value {value!r} was parsed for {target}. "
+                "YAML values for booleans, octals, floats may not yield the string you intended. "
+                """Quote the value to be explicit, like `value: "yes"`."""
+            )
+        )
+
     for element in tree.xpath(xpath, namespaces=namespaces):
         if not attribute:
             changed = changed or (element.text != value)