[configuration] Fix multi-line strings handling

Closes #3691182

2 files changed, 47 insertions, 0 deletions

diff --git a/logilab/common/configuration.py b/logilab/common/configuration.py
index bdea905..52ac6df 100644
--- a/logilab/common/configuration.py
+++ b/logilab/common/configuration.py
@@ -401,6 +401,9 @@ def ini_format(stream, options, encoding):
             print('#%s=' % optname, file=stream)
         else:
             value = _encode(value, encoding).strip()
+            if optdict.get('type') == 'string' and '\n' in value:
+                prefix = '\n    '
+                value = prefix + prefix.join(value.split('\n'))
             print('%s=%s' % (optname, value), file=stream)
 
 format_section = ini_format_section
diff --git a/test/unittest_configuration.py b/test/unittest_configuration.py
index 2a32653..f59a0e0 100644
--- a/test/unittest_configuration.py
+++ b/test/unittest_configuration.py
@@ -271,6 +271,50 @@ diffgroup=pouet
 
 #opt-b-2=""")
 
+    def test_generate_config_with_multiline_string(self):
+        self.cfg['value'] = 'line1\nline2\nline3'
+        stream = StringIO()
+        self.cfg.generate_config(stream)
+        self.assertMultiLineEqual(stream.getvalue().strip(), """[TEST]
+
+dothis=yes
+
+value=
+    line1
+    line2
+    line3
+
+# you can also document the option
+multiple=yop,yep
+
+# boom
+number=2
+
+bytes=1KB
+
+choice=yo
+
+multiple-choice=yo,ye
+
+named=key:val
+
+reset-value=
+    line1
+    line2
+    line3
+
+
+[AGROUP]
+
+diffgroup=pouet
+
+
+[BGROUP]
+
+#opt-b-1=
+
+#opt-b-2=""")
+
 
     def test_roundtrip(self):
         cfg = self.cfg