RST writer: Fix missing spaces with nested inlines.

Previously spaces around links inside italics were omitted.

Closes #8182.

src/Text/Pandoc/Writers/RST.hs

@@ -32,7 +32,7 @@ import Text.Pandoc.Shared
 import Text.Pandoc.Templates (renderTemplate)
 import Text.Pandoc.Writers.Shared
 import Text.Pandoc.Walk
-import Safe (lastMay)
+import Safe (lastMay, headMay)
 
 type Refs = [([Inline], Target)]
 
@@ -478,7 +478,18 @@ transformInlines =  insertBS .
         insertBS (x:ys) = x : insertBS ys
         insertBS [] = []
         transformNested :: [Inline] -> [Inline]
-        transformNested = map (mapNested stripLeadingTrailingSpace)
+        transformNested = concatMap exportLeadingTrailingSpace
+        exportLeadingTrailingSpace :: Inline -> [Inline]
+        exportLeadingTrailingSpace il
+          | isComplex il =
+             let contents = dropInlineParent il
+                 headSpace = headMay contents == Just Space
+                 lastSpace = lastMay contents == Just Space
+              in (if headSpace then (Space:) else id) .
+                 (if lastSpace then (++ [Space]) else id) $
+                 [setInlineChildren il (stripLeadingTrailingSpace contents)]
+          | otherwise = [il]
+
         surroundComplex :: Inline -> Inline -> Bool
         surroundComplex (Str s) (Str s')
           | Just (_, c)  <- T.unsnoc s

test/Tests/Writers/RST.hs

@@ -98,8 +98,8 @@ tests = [ testGroup "rubrics"
             strong (emph (link "loc" "" (str "text"))) =?>
             "`text <loc>`__"
           , "RST inlines cannot start nor end with spaces" =:
-            emph (str "f" <> space <> strong (str "d") <> space <> str "l") =?>
-            "*f*\\ **d**\\ *l*"
+            emph (str "f" <> strong (space <> str "d" <> space) <> str "l") =?>
+            "*f* **d** *l*"
           , "keeps quotes" =:
             strong (str "f" <> doubleQuoted (str "d") <> str "l") =?>
             "**f“d”l**"

test/command/8182.md

@@ -0,0 +1,6 @@
+```
+% pandoc -f dokuwiki -t rst
+This //text and [[https://pandoc.org/|link]] are in italic//.
+^D
+This *text and* `link <https://pandoc.org/>`__ *are in italic*.
+```