do not throw if /dev/tty cannot be opened

note that Neovim loads the syntax engine without tty emulation just fine
lyokha · May 5, 2024 · 623edb6 · 623edb6
1 parent 78c8196
commit 623edb6
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diff --git a/pandoc/haskell/Changelog.md b/pandoc/haskell/Changelog.md
@@ -1,3 +1,8 @@
+### 0.3.1.0
+
+- Do not throw if */dev/tty* cannot be opened. Note that Neovim loads the syntax
+  engine without *tty* emulation just fine.
+
 ### 0.3.0.0
 
 - Support for packages *base* &lt; *4.8* and *pandoc-types* &lt; *1.20* was

diff --git a/pandoc/haskell/pandoc-vimhl.cabal b/pandoc/haskell/pandoc-vimhl.cabal
@@ -1,5 +1,5 @@
 name:                    pandoc-vimhl
-version:                 0.3.0.0
+version:                 0.3.1.0
 synopsis:                Pandoc filter for native Vim code highlighting
 description:             Pandoc filter for native Vim code highlighting
         in HTML and PDF documents. Requires Vim (or Neovim) and plugin

diff --git a/pandoc/haskell/vimhl.hs b/pandoc/haskell/vimhl.hs
@@ -65,9 +65,24 @@ vimHl (Just fm@(Format fmt)) (CodeBlock (_, cls@(ft : _), namevals) contents)
                                 ,vimhlcmd ++ "' -c 'w!", dst ++ "' -c 'qa!'"
                                 ,src
                                 ]
+                    {- Vim must think that it was launched from a terminal,
+                     - otherwise it won't load its usual environment and the
+                     - syntax engine! Using WriteMode for stdin prevents Vim
+                     - from getting unresponsive on Ctrl-C interrupts while
+                     - still doing well its task (Vim checks that input is a
+                     - terminal using isatty(), however it does not check the
+                     - mode of the handle). Note that Neovim loads the syntax
+                     - engine just fine. -}
+                    hin <- (Just <$> openFile "/dev/tty" WriteMode)
+                        `catchIOError` const (return Nothing)
                     hout <- openFile "/dev/null" WriteMode
-                    (_, _, _, handle) <- createProcess (shell vimcmd)
-                        {std_out = UseHandle hout}
+                    (_, _, _, handle) <- createProcess $
+                        maybe (shell vimcmd) {std_out = UseHandle hout}
+                            (\hin' -> (shell vimcmd)
+                                {std_in = UseHandle hin'
+                                ,std_out = UseHandle hout
+                                }
+                            ) hin
                     r <- waitForProcess handle
                     unless (r == ExitSuccess) $ exitWith r
                     T.readFile dst