template module - Report syntax error line number (#86101)

Report the line number for Jinja syntax errors in template files.

changelogs/fragments/jinja-syntax-error-line-numbers.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - template module - Report the line number for Jinja syntax errors in template files.

lib/ansible/_internal/_templating/_jinja_bits.py

@@ -496,6 +496,14 @@ def create_template_error(ex: Exception, variable: t.Any, is_expression: bool) -
         if isinstance(ex, RecursionError):
             msg = f"Recursive loop detected in {kind}."
         elif isinstance(ex, TemplateSyntaxError):
+            if (origin := Origin.get_tag(variable)) and origin.line_num is None and ex.lineno > 0:
+                # When there is an origin without a line number, use the line number provided by the Jinja syntax error.
+                # This should only occur on templates which represent the entire contents of a file.
+                # Templates loaded from within a file, such as YAML, will use the existing origin.
+                # It's not possible to combine origins here, due to potential layout differences between the original content and the parsed output.
+                # This can happen, for example, with YAML multi-line strings.
+                variable = origin.replace(line_num=ex.lineno, col_num=None).tag(variable)
+
             msg = f"Syntax error in {kind}."
 
             if is_expression and is_possibly_template(variable):

test/integration/targets/templating-syntax-errors/aliases

@@ -0,0 +1,2 @@
+context/controller
+shippable/posix/group4

test/integration/targets/templating-syntax-errors/runme.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+set -eux
+
+ansible-playbook template-file.yml "${@}" | tee template-file.out
+
+echo "Verifying contents of error reports ..."
+
+# verify the template-file error report is correct
+grep 'template-file.j2:5' template-file.out
+grep '5 {% sorry' template-file.out
+
+echo "PASS"

test/integration/targets/templating-syntax-errors/template-file.j2

@@ -0,0 +1,5 @@
+line 1
+line 2
+line 3
+line 4
+{% sorry

test/integration/targets/templating-syntax-errors/template-file.yml

@@ -0,0 +1,7 @@
+- hosts: localhost
+  gather_facts: no
+  tasks:
+    - template:
+        src: template-file.j2
+        dest: template-file.txt
+      ignore_errors: yes