1 files changed, 47 insertions, 50 deletions

diff --git a/src/nvim/os/shell.c b/src/nvim/os/shell.c
index c205e4b3af..f650a51fe7 100644
--- a/src/nvim/os/shell.c
+++ b/src/nvim/os/shell.c
@@ -123,6 +123,9 @@ int os_call_shell(char_u *cmd, ShellOpts opts, char_u *extra_args)
     if (opts & kShellOptRead) {
       output_ptr = &output;
       forward_output = false;
+    } else if (opts & kShellOptDoOut) {
+      // Caller has already redirected output
+      forward_output = false;
     }
   }
 
@@ -257,11 +260,25 @@ static int do_os_system(char **argv,
   // busy state.
   ui_busy_start();
   ui_flush();
+  if (forward_output) {
+    msg_sb_eol();
+    msg_start();
+    msg_no_more = true;
+    lines_left = -1;
+  }
   int exitcode = process_wait(proc, -1, NULL);
   if (!got_int && out_data_decide_throttle(0)) {
     // Last chunk of output was skipped; display it now.
     out_data_ring(NULL, SIZE_MAX);
   }
+  if (forward_output) {
+    // caller should decide if wait_return is invoked
+    no_wait_return++;
+    msg_end();
+    no_wait_return--;
+    msg_no_more = false;
+  }
+
   ui_busy_stop();
 
   // prepare the out parameters if requested
@@ -405,7 +422,7 @@ static void out_data_ring(char *output, size_t size)
   }
 
   if (output == NULL && size == SIZE_MAX) {   // Print mode
-    out_data_append_to_screen(last_skipped, last_skipped_len, true);
+    out_data_append_to_screen(last_skipped, &last_skipped_len, true);
     return;
   }
 
@@ -433,60 +450,40 @@ static void out_data_ring(char *output, size_t size)
 /// @param output       Data to append to screen lines.
 /// @param remaining    Size of data.
 /// @param new_line     If true, next data output will be on a new line.
-static void out_data_append_to_screen(char *output, size_t remaining,
-                                      bool new_line)
+static void out_data_append_to_screen(char *output, size_t *count,
+                                      bool eof)
 {
-  static colnr_T last_col = 0;  // Column of last row to append to.
-
-  size_t off = 0;
-  int last_row = (int)Rows - 1;
-
-  while (output != NULL && off < remaining) {
-    // Found end of line?
-    if (output[off] == NL) {
-      // Can we start a new line or do we need to continue the last one?
-      if (last_col == 0) {
-        screen_del_lines(0, 0, 1, (int)Rows, NULL);
+  char *p = output, *end = output + *count;
+  while (p < end) {
+    if (*p == '\n' || *p == '\r' || *p == TAB || *p == BELL) {
+      msg_putchar_attr((uint8_t)(*p), 0);
+      p++;
+    } else {
+      // Note: this is not 100% precise:
+      // 1. we don't check if received continuation bytes are already invalid
+      //    and we thus do some buffering that could be avoided
+      // 2. we don't compose chars over buffer boundaries, even if we see an
+      //    incomplete UTF-8 sequence that could be composing with the last
+      //    complete sequence.
+      // This will be corrected when we switch to vterm based implementation
+      int i = *p ? mb_ptr2len_len((char_u *)p, (int)(end-p)) : 1;
+      if (!eof && i == 1 && utf8len_tab_zero[*(uint8_t *)p] > (end-p)) {
+        *count = (size_t)(p - output);
+        goto end;
       }
-      screen_puts_len((char_u *)output, (int)off, last_row, last_col, 0);
-      last_col = 0;
-
-      size_t skip = off + 1;
-      output += skip;
-      remaining -= skip;
-      off = 0;
-      continue;
-    }
 
-    // TODO(bfredl): using msg_puts would be better until
-    // terminal emulation is implemented.
-    if (output[off] < 0x20) {
-      output[off] = ' ';
+      (void)msg_outtrans_len_attr((char_u *)p, i, 0);
+      p += i;
     }
-
-    off++;
-  }
-
-  if (output != NULL && remaining) {
-    if (last_col == 0) {
-      screen_del_lines(0, 0, 1, (int)Rows, NULL);
-    }
-    screen_puts_len((char_u *)output, (int)remaining, last_row, last_col, 0);
-    last_col += (colnr_T)remaining;
-  }
-
-  if (new_line) {
-    last_col = 0;
   }
 
+end:
   ui_flush();
 }
 
 static void out_data_cb(Stream *stream, RBuffer *buf, size_t count, void *data,
     bool eof)
 {
-  // We always output the whole buffer, so the buffer can never
-  // wrap around.
   size_t cnt;
   char *ptr = rbuffer_read_ptr(buf, &cnt);
 
@@ -495,12 +492,16 @@ static void out_data_cb(Stream *stream, RBuffer *buf, size_t count, void *data,
     // Save the skipped output. If it is the final chunk, we display it later.
     out_data_ring(ptr, cnt);
   } else {
-    out_data_append_to_screen(ptr, cnt, eof);
+    out_data_append_to_screen(ptr, &cnt, eof);
   }
 
   if (cnt) {
     rbuffer_consumed(buf, cnt);
   }
+
+  // Move remaining data to start of buffer, so the buffer can never
+  // wrap around.
+  rbuffer_reset(buf);
 }
 
 /// Parses a command string into a sequence of words, taking quotes into
@@ -589,14 +590,10 @@ static void read_input(DynamicBuffer *buf)
 
     if (len == l) {
       // Finished a line, add a NL, unless this line should not have one.
-      // FIXME need to make this more readable
       if (lnum != curbuf->b_op_end.lnum
-          || (!curbuf->b_p_bin
-            && curbuf->b_p_fixeol)
+          || (!curbuf->b_p_bin && curbuf->b_p_fixeol)
           || (lnum != curbuf->b_no_eol_lnum
-            && (lnum !=
-              curbuf->b_ml.ml_line_count
-              || curbuf->b_p_eol))) {
+              && (lnum != curbuf->b_ml.ml_line_count || curbuf->b_p_eol))) {
         dynamic_buffer_ensure(buf, buf->len + 1);
         buf->data[buf->len++] = NL;
       }