1 files changed, 90 insertions, 35 deletions

diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index b5ca6543c5..90a564bb6a 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -91,6 +91,57 @@ static char *e_auabort = N_("E855: Autocommands caused command to abort");
 // Number of times free_buffer() was called.
 static int buf_free_count = 0;
 
+// Read data from buffer for retrying.
+static int
+read_buffer(
+    int     read_stdin,     // read file from stdin, otherwise fifo
+    exarg_T *eap,           // for forced 'ff' and 'fenc' or NULL
+    int     flags)          // extra flags for readfile()
+{
+  int       retval = OK;
+  linenr_T  line_count;
+
+  //
+  // Read from the buffer which the text is already filled in and append at
+  // the end.  This makes it possible to retry when 'fileformat' or
+  // 'fileencoding' was guessed wrong.
+  //
+  line_count = curbuf->b_ml.ml_line_count;
+  retval = readfile(
+      read_stdin ? NULL : curbuf->b_ffname,
+      read_stdin ? NULL : curbuf->b_fname,
+      (linenr_T)line_count, (linenr_T)0, (linenr_T)MAXLNUM, eap,
+      flags | READ_BUFFER);
+  if (retval == OK) {
+    // Delete the binary lines.
+    while (--line_count >= 0) {
+      ml_delete((linenr_T)1, false);
+    }
+  } else {
+    // Delete the converted lines.
+    while (curbuf->b_ml.ml_line_count > line_count) {
+      ml_delete(line_count, false);
+    }
+  }
+  // Put the cursor on the first line.
+  curwin->w_cursor.lnum = 1;
+  curwin->w_cursor.col = 0;
+
+  if (read_stdin) {
+    // Set or reset 'modified' before executing autocommands, so that
+    // it can be changed there.
+    if (!readonlymode && !bufempty()) {
+      changed();
+    } else if (retval != FAIL) {
+      unchanged(curbuf, false);
+    }
+
+    apply_autocmds_retval(EVENT_STDINREADPOST, NULL, NULL, false,
+                          curbuf, &retval);
+  }
+  return retval;
+}
+
 /*
  * Open current buffer, that is: open the memfile and read the file into
  * memory.
@@ -106,6 +157,7 @@ open_buffer (
   int retval = OK;
   bufref_T       old_curbuf;
   long old_tw = curbuf->b_p_tw;
+  int read_fifo = false;
 
   /*
    * The 'readonly' flag is only set when BF_NEVERLOADED is being reset.
@@ -156,13 +208,45 @@ open_buffer (
 
   if (curbuf->b_ffname != NULL) {
     int old_msg_silent = msg_silent;
+#ifdef UNIX
+    int save_bin = curbuf->b_p_bin;
+    int perm;
+
+    perm = os_getperm((const char *)curbuf->b_ffname);
+    if (perm >= 0 && (0
+# ifdef S_ISFIFO
+                      || S_ISFIFO(perm)
+# endif
+# ifdef S_ISSOCK
+                      || S_ISSOCK(perm)
+# endif
+# ifdef OPEN_CHR_FILES
+                      || (S_ISCHR(perm)
+                          && is_dev_fd_file(curbuf->b_ffname))
+# endif
+                      )
+        ) {
+      read_fifo = true;
+    }
+    if (read_fifo) {
+      curbuf->b_p_bin = true;
+    }
+#endif
     if (shortmess(SHM_FILEINFO)) {
       msg_silent = 1;
     }
 
     retval = readfile(curbuf->b_ffname, curbuf->b_fname,
                       (linenr_T)0, (linenr_T)0, (linenr_T)MAXLNUM, eap,
-                      flags | READ_NEW);
+                      flags | READ_NEW | (read_fifo ? READ_FIFO : 0));
+#ifdef UNIX
+    if (read_fifo) {
+      curbuf->b_p_bin = save_bin;
+      if (retval == OK) {
+        retval = read_buffer(false, eap, flags);
+      }
+    }
+#endif
     msg_silent = old_msg_silent;
 
     // Help buffer is filtered.
@@ -171,7 +255,6 @@ open_buffer (
     }
   } else if (read_stdin) {
     int save_bin = curbuf->b_p_bin;
-    linenr_T line_count;
 
     /*
      * First read the text in binary mode into the buffer.
@@ -185,41 +268,13 @@ open_buffer (
         flags | (READ_NEW + READ_STDIN));
     curbuf->b_p_bin = save_bin;
     if (retval == OK) {
-      line_count = curbuf->b_ml.ml_line_count;
-      retval = readfile(NULL, NULL, (linenr_T)line_count,
-          (linenr_T)0, (linenr_T)MAXLNUM, eap,
-          flags | READ_BUFFER);
-      if (retval == OK) {
-        /* Delete the binary lines. */
-        while (--line_count >= 0)
-          ml_delete((linenr_T)1, FALSE);
-      } else {
-        /* Delete the converted lines. */
-        while (curbuf->b_ml.ml_line_count > line_count)
-          ml_delete(line_count, FALSE);
-      }
-      /* Put the cursor on the first line. */
-      curwin->w_cursor.lnum = 1;
-      curwin->w_cursor.col = 0;
-
-      // Set or reset 'modified' before executing autocommands, so that
-      // it can be changed there.
-      if (!readonlymode && !bufempty()) {
-        changed();
-      } else if (retval == OK) {
-        unchanged(curbuf, false);
-      }
-
-      if (retval == OK) {
-        apply_autocmds_retval(EVENT_STDINREADPOST, NULL, NULL, false,
-                              curbuf, &retval);
-      }
+      retval = read_buffer(true, eap, flags);
     }
   }
 
   /* if first time loading this buffer, init b_chartab[] */
   if (curbuf->b_flags & BF_NEVERLOADED) {
-    (void)buf_init_chartab(curbuf, FALSE);
+    (void)buf_init_chartab(curbuf, false);
     parse_cino(curbuf);
   }
 
@@ -234,7 +289,7 @@ open_buffer (
       || modified_was_set               // ":set modified" used in autocmd
       || (aborting() && vim_strchr(p_cpo, CPO_INTMOD) != NULL)) {
     changed();
-  } else if (retval == OK && !read_stdin) {
+  } else if (retval != FAIL && !read_stdin && !read_fifo) {
     unchanged(curbuf, false);
   }
   save_file_ff(curbuf);                 // keep this fileformat
@@ -416,8 +471,8 @@ void close_buffer(win_T *win, buf_T *buf, int action, int abort_if_last)
       return;
     }
 
-    /* When the buffer becomes hidden, but is not unloaded, trigger
-     * BufHidden */
+    // When the buffer becomes hidden, but is not unloaded, trigger
+    // BufHidden
     if (!unload_buf) {
       buf->b_locked++;
       if (apply_autocmds(EVENT_BUFHIDDEN, buf->b_fname, buf->b_fname, false,