Org reader: fix parsing of src blocks with an -i flag.

Tabs are now preserved in the contents of *src* blocks if the the block
has the `-i` flag.

Fixes: #10071

src/Text/Pandoc/Readers/Org/Blocks.hs

@@ -245,10 +245,12 @@ rawBlockContent blockType = try $ do
   blkLines <- manyTill rawLine blockEnder
   tabLen <- getOption readerTabStop
   trimP <- orgStateTrimLeadBlkIndent <$> getState
-  let stripIndent strs = if trimP then map (T.drop (shortestIndent strs)) strs else strs
+  let stripIndent strs = map (T.drop (shortestIndent strs)) strs
   (T.unlines
-   . stripIndent
-   . map (tabsToSpaces tabLen . commaEscaped)
+   . (if trimP
+      then stripIndent . map (tabsToSpaces tabLen)
+      else id)
+   . map commaEscaped
    $ blkLines)
    <$ updateState (\s -> s { orgStateTrimLeadBlkIndent = True })
  where

test/command/10071.md

@@ -0,0 +1,15 @@
+Leading tabs must be preserved in org mode *src* blocks with the `-i`
+flag when pandoc is called with `-p`/`--preserve-tabs`.
+
+```
+% pandoc -f org -t native --preserve-tabs
+#+begin_src makefile -i
+%.o: %.cpp
+	$(CXX)	-o	$@	$<
+#+end_src
+^D
+[ CodeBlock
+    ( "" , [ "makefile" ] , [] )
+    "%.o: %.cpp\n\t$(CXX)\t-o\t$@\t$<\n"
+]
+```