Teach screen how to render completion page. Correct spacing in

completion page contents.

pager.cpp

@@ -416,6 +416,7 @@ line_t pager_t::completion_print_item(const wcstring &prefix, const comp_t *c, s
             written += print_max(L" ", 0, 1, false, &line_data);
         }
     }
+
     return line_data;
 }
 
@@ -436,6 +437,8 @@ void pager_t::completion_print(int cols, int *width_per_column, int row_start, i
 
     size_t rows = (lst.size()-1)/cols+1;
 
+    fprintf(stderr, "prefix: %ls\n", prefix.c_str());
+
     for (size_t row = row_start; row < row_stop; row++)
     {
         for (size_t col = 0; col < cols; col++)
@@ -450,6 +453,13 @@ void pager_t::completion_print(int cols, int *width_per_column, int row_start, i
             /* Print this completion on its own "line" */
             line_t line = completion_print_item(prefix, el, row, col, width_per_column[col] - (is_last?0:2), row%2, rendering);
             
+            /* If there's more to come, append two spaces */
+            if (col + 1 < cols)
+            {
+                line.append(L' ', 0);
+                line.append(L' ', 0);
+            }
+            
             /* Append this to the real line */
             rendering->screen_data.create_line(row).append_line(line);
         }

parse_productions.cpp

@@ -126,7 +126,7 @@ RESOLVE(statement)
     if (token1.type == parse_token_type_string)
     {
         // If we are a function, then look for help arguments
-        // Othewrise, if the next token looks like an option (starts with a dash), then parse it as a decorated statement
+        // Otherwise, if the next token looks like an option (starts with a dash), then parse it as a decorated statement
         if (token1.keyword == parse_keyword_function && token2.is_help_argument)
         {
             return 4;

reader.cpp

@@ -100,6 +100,7 @@ commence.
 #include "parse_util.h"
 #include "parser_keywords.h"
 #include "parse_tree.h"
+#include "pager.h"
 
 /**
    Maximum length of prefix string when printing completion
@@ -199,6 +200,9 @@ public:
 
     /** String containing the autosuggestion */
     wcstring autosuggestion;
+    
+    /** Current completions */
+    page_rendering_t completion_page_rendering;
 
     /** Whether autosuggesting is allowed at all */
     bool allow_autosuggestion;
@@ -541,7 +545,8 @@ static void reader_repaint()
             data->command_length(),
             &colors[0],
             &indents[0],
-            data->buff_pos);
+            data->buff_pos,
+            &data->completion_page_rendering.screen_data);
 
     data->repaint_needed = false;
 }
@@ -1852,14 +1857,25 @@ static bool handle_completions(const std::vector<completion_t> &comp)
                 wchar_t quote;
                 parse_util_get_parameter_info(data->command_line, data->buff_pos, &quote, NULL, NULL);
                 is_quoted = (quote != L'\0');
+                
+                if (1)
+                {
+                    pager_t pager;
+                    pager.set_term_size(common_get_width(), common_get_height());
+                    pager.prefix = prefix;
+                    pager.set_completions(surviving_completions);
+                    data->completion_page_rendering = pager.render();
+                }
+                else
+                {
+                    /* Clear the autosuggestion from the old commandline before abandoning it (see #561) */
+                    if (! data->autosuggestion.empty())
+                        reader_repaint_without_autosuggestion();
 
-                /* Clear the autosuggestion from the old commandline before abandoning it (see #561) */
-                if (! data->autosuggestion.empty())
-                    reader_repaint_without_autosuggestion();
+                    write_loop(1, "\n", 1);
 
-                write_loop(1, "\n", 1);
-
-                run_pager(prefix, is_quoted, surviving_completions);
+                    run_pager(prefix, is_quoted, surviving_completions);
+                }
             }
             s_reset(&data->screen, screen_reset_abandon_line);
             reader_repaint();
@@ -3189,7 +3205,7 @@ const wchar_t *reader_readline(void)
                     /* Munge our completions */
                     sort_and_make_unique(comp);
                     prioritize_completions(comp);
-
+                    
                     /* Record our cycle_command_line */
                     cycle_command_line = data->command_line;
                     cycle_cursor_pos = data->buff_pos;

screen.cpp

@@ -1234,7 +1234,8 @@ void s_write(screen_t *s,
              size_t explicit_len,
              const int *colors,
              const int *indent,
-             size_t cursor_pos)
+             size_t cursor_pos,
+             const screen_data_t *pager_data)
 {
     screen_data_t::cursor_t cursor_arr;
 
@@ -1321,6 +1322,13 @@ void s_write(screen_t *s,
     }
 
     s->desired.cursor = cursor_arr;
+    
+    /* append pager_data */
+    if (pager_data != NULL)
+    {
+        s->desired.append_lines(*pager_data);
+    }
+    
     s_update(s, layout.left_prompt.c_str(), layout.right_prompt.c_str());
     s_save_status(s);
 }

screen.h

@@ -109,6 +109,11 @@ class screen_data_t
     {
         return line_datas.size();
     }
+    
+    void append_lines(const screen_data_t &d)
+    {
+        this->line_datas.insert(this->line_datas.end(), d.line_datas.begin(), d.line_datas.end());
+    }
 };
 
 /**
@@ -196,7 +201,8 @@ void s_write(screen_t *s,
              size_t explicit_len,
              const int *colors,
              const int *indent,
-             size_t cursor_pos);
+             size_t cursor_pos,
+             const screen_data_t *pager_data);
 
 /**
     This function resets the screen buffers internal knowledge about