Added `--default-image-extension` and `readerDefaultImageExtension`.

Note: Currently this only affects the markdown reader.

2 files changed, 20 insertions, 13 deletions

diff --git a/src/Text/Pandoc/Options.hs b/src/Text/Pandoc/Options.hs
index f67debf97..1ba8a6dd6 100644
--- a/src/Text/Pandoc/Options.hs
+++ b/src/Text/Pandoc/Options.hs
@@ -204,22 +204,24 @@ data ReaderOptions = ReaderOptions{
        , readerApplyMacros     :: Bool -- ^ Apply macros to TeX math
        , readerIndentedCodeClasses :: [String] -- ^ Default classes for
                                        -- indented code blocks
+       , readerDefaultImageExtension :: String -- ^ Default extension for images
 } deriving (Show, Read)
 
 instance Default ReaderOptions
   where def = ReaderOptions{
-                 readerExtensions          = pandocExtensions
-               , readerSmart               = False
-               , readerStrict              = False
-               , readerStandalone          = False
-               , readerParseRaw            = False
-               , readerColumns             = 80
-               , readerTabStop             = 4
-               , readerOldDashes           = False
-               , readerReferences          = []
-               , readerCitationStyle       = Nothing
-               , readerApplyMacros         = True
-               , readerIndentedCodeClasses = []
+                 readerExtensions            = pandocExtensions
+               , readerSmart                 = False
+               , readerStrict                = False
+               , readerStandalone            = False
+               , readerParseRaw              = False
+               , readerColumns               = 80
+               , readerTabStop               = 4
+               , readerOldDashes             = False
+               , readerReferences            = []
+               , readerCitationStyle         = Nothing
+               , readerApplyMacros           = True
+               , readerIndentedCodeClasses   = []
+               , readerDefaultImageExtension = ""
                }
 
 --
diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index dc30e17ed..6b144f35e 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -51,6 +51,7 @@ import qualified Text.CSL as CSL
 import Data.Monoid (mconcat, mempty)
 import Control.Applicative ((<$>), (<*), (*>), (<$))
 import Control.Monad
+import System.FilePath (takeExtension, addExtension)
 import Text.HTML.TagSoup
 import Text.HTML.TagSoup.Match (tagOpen)
 import qualified Data.Set as Set
@@ -1561,7 +1562,11 @@ image :: MarkdownParser (F Inlines)
 image = try $ do
   char '!'
   (lab,raw) <- reference
-  regLink B.image lab <|> referenceLink B.image (lab,raw)
+  defaultExt <- getOption readerDefaultImageExtension
+  let constructor src = case takeExtension src of
+                              "" -> B.image (addExtension src defaultExt)
+                              _  -> B.image src
+  regLink constructor lab <|> referenceLink constructor (lab,raw)
 
 note :: MarkdownParser (F Inlines)
 note = try $ do