Partially revert "Remove --no-print-logs option"

We'll deprecate --no-print-logs beginning with pytest-4.0.

This reverts commit ac7eb63a6b.

_pytest/logging.py

@@ -84,6 +84,11 @@ def pytest_addoption(parser):
                       help='default value for ' + option)
         group.addoption(option, dest=dest, **kwargs)
 
+    add_option_ini(
+        '--no-print-logs',
+        dest='log_print', action='store_const', const=False, default=True,
+        type='bool',
+        help='disable printing caught logs on failed tests.')
     add_option_ini(
         '--log-level',
         dest='log_level', default=None,
@@ -338,6 +343,7 @@ class LoggingPlugin(object):
             assert self._config.pluginmanager.get_plugin('terminalreporter') is None
             config.option.verbose = 1
 
+        self.print_logs = get_option_ini(config, 'log_print')
         self.formatter = logging.Formatter(get_option_ini(config, 'log_format'),
                                            get_option_ini(config, 'log_date_format'))
         self.log_level = get_actual_log_level(config, 'log_level')
@@ -388,6 +394,7 @@ class LoggingPlugin(object):
                 if when == 'teardown':
                     del item.catch_log_handlers
 
+            if self.print_logs:
                 # Add a captured log section to the report.
                 log = log_handler.stream.getvalue().strip()
                 item.add_report_section(when, 'log', log)

testing/logging/test_reporting.py

@@ -91,6 +91,60 @@ def test_teardown_logging(testdir):
                                  '*text going to logger from teardown*'])
 
 
+def test_disable_log_capturing(testdir):
+    testdir.makepyfile('''
+        import sys
+        import logging
+
+        logger = logging.getLogger(__name__)
+
+        def test_foo():
+            sys.stdout.write('text going to stdout')
+            logger.warning('catch me if you can!')
+            sys.stderr.write('text going to stderr')
+            assert False
+        ''')
+    result = testdir.runpytest('--no-print-logs')
+    print(result.stdout)
+    assert result.ret == 1
+    result.stdout.fnmatch_lines(['*- Captured stdout call -*',
+                                 'text going to stdout'])
+    result.stdout.fnmatch_lines(['*- Captured stderr call -*',
+                                 'text going to stderr'])
+    with pytest.raises(pytest.fail.Exception):
+        result.stdout.fnmatch_lines(['*- Captured *log call -*'])
+
+
+def test_disable_log_capturing_ini(testdir):
+    testdir.makeini(
+        '''
+        [pytest]
+        log_print=False
+        '''
+    )
+    testdir.makepyfile('''
+        import sys
+        import logging
+
+        logger = logging.getLogger(__name__)
+
+        def test_foo():
+            sys.stdout.write('text going to stdout')
+            logger.warning('catch me if you can!')
+            sys.stderr.write('text going to stderr')
+            assert False
+        ''')
+    result = testdir.runpytest()
+    print(result.stdout)
+    assert result.ret == 1
+    result.stdout.fnmatch_lines(['*- Captured stdout call -*',
+                                 'text going to stdout'])
+    result.stdout.fnmatch_lines(['*- Captured stderr call -*',
+                                 'text going to stderr'])
+    with pytest.raises(pytest.fail.Exception):
+        result.stdout.fnmatch_lines(['*- Captured *log call -*'])
+
+
 @pytest.mark.parametrize('enabled', [True, False])
 def test_log_cli_enabled_disabled(testdir, enabled):
     msg = 'critical message logged by test'