vim-patch:8.2.1587: loop for handling keys for the command line is too long (#19868)

Problem:    Loop for handling keys for the command line is too long.
Solution:   Move wild menu handling to separate functions. (Yegappan
            Lakshmanan, closes vim/vim#6856)
https://github.com/vim/vim/commit/eadee486c70946ad0e1746d77898d6f4f4acc817

3 files changed, 233 insertions, 206 deletions

diff --git a/src/nvim/cmdexpand.c b/src/nvim/cmdexpand.c
index 28806094d6..dd5251e761 100644
--- a/src/nvim/cmdexpand.c
+++ b/src/nvim/cmdexpand.c
@@ -10,6 +10,7 @@
 #include "nvim/charset.h"
 #include "nvim/cmdexpand.h"
 #include "nvim/cmdhist.h"
+#include "nvim/drawscreen.h"
 #include "nvim/eval.h"
 #include "nvim/eval/funcs.h"
 #include "nvim/eval/userfunc.h"
@@ -40,6 +41,7 @@
 #include "nvim/ui.h"
 #include "nvim/usercmd.h"
 #include "nvim/vim.h"
+#include "nvim/window.h"
 
 /// Type used by ExpandGeneric()
 typedef char *(*CompleteListItemGetter)(expand_T *, int);
@@ -53,15 +55,13 @@ typedef void *(*user_expand_func_T)(const char_u *, int, typval_T *);
 
 static int cmd_showtail;  ///< Only show path tail in lists ?
 
-// TODO(zeertzjq): make these four variables static in cmdexpand.c
-
 /// "compl_match_array" points the currently displayed list of entries in the
 /// popup menu.  It is NULL when there is no popup menu.
-pumitem_T *compl_match_array = NULL;
-int compl_match_arraysize;
+pumitem_T *compl_match_array = NULL;  // TODO(zeertzjq): make this static in cmdexpand.c
+static int compl_match_arraysize;
 /// First column in cmdline of the matched item for completion.
-int compl_startcol;
-int compl_selected;
+static int compl_startcol;
+static int compl_selected;
 
 static int sort_func_compare(const void *s1, const void *s2)
 {
@@ -2509,6 +2509,227 @@ void globpath(char *path, char_u *file, garray_T *ga, int expand_options)
   xfree(buf);
 }
 
+/// Translate some keys pressed when 'wildmenu' is used.
+int wildmenu_translate_key(CmdlineInfo *cclp, int key, expand_T *xp, int did_wild_list)
+{
+  int c = key;
+
+  if (did_wild_list && p_wmnu) {
+    if (c == K_LEFT) {
+      c = Ctrl_P;
+    } else if (c == K_RIGHT) {
+      c = Ctrl_N;
+    }
+  }
+  // Hitting CR after "emenu Name.": complete submenu
+  if (xp->xp_context == EXPAND_MENUNAMES && p_wmnu
+      && cclp->cmdpos > 1
+      && cclp->cmdbuff[cclp->cmdpos - 1] == '.'
+      && cclp->cmdbuff[cclp->cmdpos - 2] != '\\'
+      && (c == '\n' || c == '\r' || c == K_KENTER)) {
+    c = K_DOWN;
+  }
+
+  return c;
+}
+
+/// Delete characters on the command line, from "from" to the current position.
+static void cmdline_del(CmdlineInfo *cclp, int from)
+{
+  assert(cclp->cmdpos <= cclp->cmdlen);
+  memmove(cclp->cmdbuff + from, cclp->cmdbuff + cclp->cmdpos,
+          (size_t)cclp->cmdlen - (size_t)cclp->cmdpos + 1);
+  cclp->cmdlen -= cclp->cmdpos - from;
+  cclp->cmdpos = from;
+}
+
+/// Handle a key pressed when wild menu is displayed
+int wildmenu_process_key(CmdlineInfo *cclp, int key, expand_T *xp)
+{
+  int c = key;
+
+  if (!p_wmnu) {
+    return c;
+  }
+
+  // Special translations for 'wildmenu'
+  if (xp->xp_context == EXPAND_MENUNAMES) {
+    // Hitting <Down> after "emenu Name.": complete submenu
+    if (c == K_DOWN && cclp->cmdpos > 0
+        && cclp->cmdbuff[cclp->cmdpos - 1] == '.') {
+      c = (int)p_wc;
+      KeyTyped = true;  // in case the key was mapped
+    } else if (c == K_UP) {
+      // Hitting <Up>: Remove one submenu name in front of the
+      // cursor
+      int found = false;
+
+      int j = (int)((char_u *)xp->xp_pattern - cclp->cmdbuff);
+      int i = 0;
+      while (--j > 0) {
+        // check for start of menu name
+        if (cclp->cmdbuff[j] == ' '
+            && cclp->cmdbuff[j - 1] != '\\') {
+          i = j + 1;
+          break;
+        }
+
+        // check for start of submenu name
+        if (cclp->cmdbuff[j] == '.'
+            && cclp->cmdbuff[j - 1] != '\\') {
+          if (found) {
+            i = j + 1;
+            break;
+          } else {
+            found = true;
+          }
+        }
+      }
+      if (i > 0) {
+        cmdline_del(cclp, i);
+      }
+      c = (int)p_wc;
+      KeyTyped = true;  // in case the key was mapped
+      xp->xp_context = EXPAND_NOTHING;
+    }
+  }
+  if (xp->xp_context == EXPAND_FILES
+      || xp->xp_context == EXPAND_DIRECTORIES
+      || xp->xp_context == EXPAND_SHELLCMD) {
+    char_u upseg[5];
+
+    upseg[0] = PATHSEP;
+    upseg[1] = '.';
+    upseg[2] = '.';
+    upseg[3] = PATHSEP;
+    upseg[4] = NUL;
+
+    if (c == K_DOWN
+        && cclp->cmdpos > 0
+        && cclp->cmdbuff[cclp->cmdpos - 1] == PATHSEP
+        && (cclp->cmdpos < 3
+            || cclp->cmdbuff[cclp->cmdpos - 2] != '.'
+            || cclp->cmdbuff[cclp->cmdpos - 3] != '.')) {
+      // go down a directory
+      c = (int)p_wc;
+      KeyTyped = true;  // in case the key was mapped
+    } else if (STRNCMP(xp->xp_pattern, upseg + 1, 3) == 0
+               && c == K_DOWN) {
+      // If in a direct ancestor, strip off one ../ to go down
+      int found = false;
+
+      int j = cclp->cmdpos;
+      int i = (int)((char_u *)xp->xp_pattern - cclp->cmdbuff);
+      while (--j > i) {
+        j -= utf_head_off(cclp->cmdbuff, cclp->cmdbuff + j);
+        if (vim_ispathsep(cclp->cmdbuff[j])) {
+          found = true;
+          break;
+        }
+      }
+      if (found
+          && cclp->cmdbuff[j - 1] == '.'
+          && cclp->cmdbuff[j - 2] == '.'
+          && (vim_ispathsep(cclp->cmdbuff[j - 3]) || j == i + 2)) {
+        cmdline_del(cclp, j - 2);
+        c = (int)p_wc;
+        KeyTyped = true;  // in case the key was mapped
+      }
+    } else if (c == K_UP) {
+      // go up a directory
+      int found = false;
+
+      int j = cclp->cmdpos - 1;
+      int i = (int)((char_u *)xp->xp_pattern - cclp->cmdbuff);
+      while (--j > i) {
+        j -= utf_head_off(cclp->cmdbuff, cclp->cmdbuff + j);
+        if (vim_ispathsep(cclp->cmdbuff[j])
+#ifdef BACKSLASH_IN_FILENAME
+            && vim_strchr((const char_u *)" *?[{`$%#", cclp->cmdbuff[j + 1])
+            == NULL
+#endif
+            ) {
+          if (found) {
+            i = j + 1;
+            break;
+          } else {
+            found = true;
+          }
+        }
+      }
+
+      if (!found) {
+        j = i;
+      } else if (STRNCMP(cclp->cmdbuff + j, upseg, 4) == 0) {
+        j += 4;
+      } else if (STRNCMP(cclp->cmdbuff + j, upseg + 1, 3) == 0
+                 && j == i) {
+        j += 3;
+      } else {
+        j = 0;
+      }
+
+      if (j > 0) {
+        // TODO(tarruda): this is only for DOS/Unix systems - need to put in
+        // machine-specific stuff here and in upseg init
+        cmdline_del(cclp, j);
+        put_on_cmdline(upseg + 1, 3, false);
+      } else if (cclp->cmdpos > i) {
+        cmdline_del(cclp, i);
+      }
+
+      // Now complete in the new directory. Set KeyTyped in case the
+      // Up key came from a mapping.
+      c = (int)p_wc;
+      KeyTyped = true;
+    }
+  }
+
+  return c;
+}
+
+/// Free expanded names when finished walking through the matches
+void wildmenu_cleanup(CmdlineInfo *cclp)
+{
+  if (!p_wmnu || wild_menu_showing == 0) {
+    return;
+  }
+
+  const bool skt = KeyTyped;
+  int old_RedrawingDisabled = RedrawingDisabled;
+
+  if (cclp->input_fn) {
+    RedrawingDisabled = 0;
+  }
+
+  if (wild_menu_showing == WM_SCROLLED) {
+    // Entered command line, move it up
+    cmdline_row--;
+    redrawcmd();
+    wild_menu_showing = 0;
+  } else if (save_p_ls != -1) {
+    // restore 'laststatus' and 'winminheight'
+    p_ls = save_p_ls;
+    p_wmh = save_p_wmh;
+    last_status(false);
+    update_screen(VALID);                 // redraw the screen NOW
+    redrawcmd();
+    save_p_ls = -1;
+    wild_menu_showing = 0;
+    // don't redraw statusline if WM_LIST is showing
+  } else if (wild_menu_showing != WM_LIST) {
+    win_redraw_last_status(topframe);
+    wild_menu_showing = 0;  // must be before redraw_statuslines #8385
+    redraw_statuslines();
+  } else {
+    wild_menu_showing = 0;
+  }
+  KeyTyped = skt;
+  if (cclp->input_fn) {
+    RedrawingDisabled = old_RedrawingDisabled;
+  }
+}
+
 /// "getcompletion()" function
 void f_getcompletion(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 {
diff --git a/src/nvim/cmdexpand.h b/src/nvim/cmdexpand.h
index f534a2e0d3..93e91af169 100644
--- a/src/nvim/cmdexpand.h
+++ b/src/nvim/cmdexpand.h
@@ -2,6 +2,7 @@
 #define NVIM_CMDEXPAND_H
 
 #include "nvim/eval/typval.h"
+#include "nvim/ex_getln.h"
 #include "nvim/garray.h"
 #include "nvim/types.h"
 
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index c14eca6604..ec6c4af18a 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -170,12 +170,7 @@ static Array cmdline_block = ARRAY_DICT_INIT;
 /// user interrupting highlight function to not interrupt command-line.
 static bool getln_interrupted_highlight = false;
 
-// TODO(zeertzjq): make these four variables static in cmdexpand.c
-
-extern pumitem_T *compl_match_array;
-extern int compl_match_arraysize;
-extern int compl_startcol;
-extern int compl_selected;
+extern pumitem_T *compl_match_array;  // TODO(zeertzjq): make this static in cmdexpand.c
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "ex_getln.c.generated.h"
@@ -1028,14 +1023,8 @@ static int command_line_execute(VimState *state, int key)
     s->c = Ctrl_P;
   }
 
-  // Special translations for 'wildmenu'
-  if (s->did_wild_list && p_wmnu) {
-    if (s->c == K_LEFT) {
-      s->c = Ctrl_P;
-    } else if (s->c == K_RIGHT) {
-      s->c = Ctrl_N;
-    }
-  }
+  s->c = wildmenu_translate_key(&ccline, s->c, &s->xpc, s->did_wild_list);
+
   if (compl_match_array || s->did_wild_list) {
     if (s->c == Ctrl_E) {
       s->res = nextwild(&s->xpc, WILD_CANCEL, WILD_NO_BEEP,
@@ -1047,15 +1036,6 @@ static int command_line_execute(VimState *state, int key)
     }
   }
 
-  // Hitting CR after "emenu Name.": complete submenu
-  if (s->xpc.xp_context == EXPAND_MENUNAMES && p_wmnu
-      && ccline.cmdpos > 1
-      && ccline.cmdbuff[ccline.cmdpos - 1] == '.'
-      && ccline.cmdbuff[ccline.cmdpos - 2] != '\\'
-      && (s->c == '\n' || s->c == '\r' || s->c == K_KENTER)) {
-    s->c = K_DOWN;
-  }
-
   // free expanded names when finished walking through matches
   if (!(s->c == p_wc && KeyTyped) && s->c != p_wcm && s->c != Ctrl_Z
       && s->c != Ctrl_N && s->c != Ctrl_P && s->c != Ctrl_A
@@ -1072,175 +1052,10 @@ static int command_line_execute(VimState *state, int key)
       s->xpc.xp_context = EXPAND_NOTHING;
     }
     s->wim_index = 0;
-    if (p_wmnu && wild_menu_showing != 0) {
-      const bool skt = KeyTyped;
-      int old_RedrawingDisabled = RedrawingDisabled;
-
-      if (ccline.input_fn) {
-        RedrawingDisabled = 0;
-      }
-
-      if (wild_menu_showing == WM_SCROLLED) {
-        // Entered command line, move it up
-        cmdline_row--;
-        redrawcmd();
-        wild_menu_showing = 0;
-      } else if (save_p_ls != -1) {
-        // restore 'laststatus' and 'winminheight'
-        p_ls = save_p_ls;
-        p_wmh = save_p_wmh;
-        last_status(false);
-        update_screen(VALID);                 // redraw the screen NOW
-        redrawcmd();
-        save_p_ls = -1;
-        wild_menu_showing = 0;
-        // don't redraw statusline if WM_LIST is showing
-      } else if (wild_menu_showing != WM_LIST) {
-        win_redraw_last_status(topframe);
-        wild_menu_showing = 0;  // must be before redraw_statuslines #8385
-        redraw_statuslines();
-      } else {
-        wild_menu_showing = 0;
-      }
-      KeyTyped = skt;
-      if (ccline.input_fn) {
-        RedrawingDisabled = old_RedrawingDisabled;
-      }
-    }
-  }
-
-  // Special translations for 'wildmenu'
-  if (s->xpc.xp_context == EXPAND_MENUNAMES && p_wmnu) {
-    // Hitting <Down> after "emenu Name.": complete submenu
-    if (s->c == K_DOWN && ccline.cmdpos > 0
-        && ccline.cmdbuff[ccline.cmdpos - 1] == '.') {
-      s->c = (int)p_wc;
-      KeyTyped = true;  // in case the key was mapped
-    } else if (s->c == K_UP) {
-      // Hitting <Up>: Remove one submenu name in front of the
-      // cursor
-      int found = false;
-
-      int j = (int)((char_u *)s->xpc.xp_pattern - ccline.cmdbuff);
-      int i = 0;
-      while (--j > 0) {
-        // check for start of menu name
-        if (ccline.cmdbuff[j] == ' '
-            && ccline.cmdbuff[j - 1] != '\\') {
-          i = j + 1;
-          break;
-        }
-
-        // check for start of submenu name
-        if (ccline.cmdbuff[j] == '.'
-            && ccline.cmdbuff[j - 1] != '\\') {
-          if (found) {
-            i = j + 1;
-            break;
-          } else {
-            found = true;
-          }
-        }
-      }
-      if (i > 0) {
-        cmdline_del(i);
-      }
-      s->c = (int)p_wc;
-      KeyTyped = true;  // in case the key was mapped
-      s->xpc.xp_context = EXPAND_NOTHING;
-    }
+    wildmenu_cleanup(&ccline);
   }
-  if ((s->xpc.xp_context == EXPAND_FILES
-       || s->xpc.xp_context == EXPAND_DIRECTORIES
-       || s->xpc.xp_context == EXPAND_SHELLCMD) && p_wmnu) {
-    char_u upseg[5];
-
-    upseg[0] = PATHSEP;
-    upseg[1] = '.';
-    upseg[2] = '.';
-    upseg[3] = PATHSEP;
-    upseg[4] = NUL;
-
-    if (s->c == K_DOWN
-        && ccline.cmdpos > 0
-        && ccline.cmdbuff[ccline.cmdpos - 1] == PATHSEP
-        && (ccline.cmdpos < 3
-            || ccline.cmdbuff[ccline.cmdpos - 2] != '.'
-            || ccline.cmdbuff[ccline.cmdpos - 3] != '.')) {
-      // go down a directory
-      s->c = (int)p_wc;
-      KeyTyped = true;  // in case the key was mapped
-    } else if (STRNCMP(s->xpc.xp_pattern, upseg + 1, 3) == 0
-               && s->c == K_DOWN) {
-      // If in a direct ancestor, strip off one ../ to go down
-      int found = false;
-
-      int j = ccline.cmdpos;
-      int i = (int)((char_u *)s->xpc.xp_pattern - ccline.cmdbuff);
-      while (--j > i) {
-        j -= utf_head_off(ccline.cmdbuff, ccline.cmdbuff + j);
-        if (vim_ispathsep(ccline.cmdbuff[j])) {
-          found = true;
-          break;
-        }
-      }
-      if (found
-          && ccline.cmdbuff[j - 1] == '.'
-          && ccline.cmdbuff[j - 2] == '.'
-          && (vim_ispathsep(ccline.cmdbuff[j - 3]) || j == i + 2)) {
-        cmdline_del(j - 2);
-        s->c = (int)p_wc;
-        KeyTyped = true;  // in case the key was mapped
-      }
-    } else if (s->c == K_UP) {
-      // go up a directory
-      int found = false;
-
-      int j = ccline.cmdpos - 1;
-      int i = (int)((char_u *)s->xpc.xp_pattern - ccline.cmdbuff);
-      while (--j > i) {
-        j -= utf_head_off(ccline.cmdbuff, ccline.cmdbuff + j);
-        if (vim_ispathsep(ccline.cmdbuff[j])
-#ifdef BACKSLASH_IN_FILENAME
-            && vim_strchr((const char_u *)" *?[{`$%#", ccline.cmdbuff[j + 1])
-            == NULL
-#endif
-            ) {
-          if (found) {
-            i = j + 1;
-            break;
-          } else {
-            found = true;
-          }
-        }
-      }
 
-      if (!found) {
-        j = i;
-      } else if (STRNCMP(ccline.cmdbuff + j, upseg, 4) == 0) {
-        j += 4;
-      } else if (STRNCMP(ccline.cmdbuff + j, upseg + 1, 3) == 0
-                 && j == i) {
-        j += 3;
-      } else {
-        j = 0;
-      }
-
-      if (j > 0) {
-        // TODO(tarruda): this is only for DOS/Unix systems - need to put in
-        // machine-specific stuff here and in upseg init
-        cmdline_del(j);
-        put_on_cmdline(upseg + 1, 3, false);
-      } else if (ccline.cmdpos > i) {
-        cmdline_del(i);
-      }
-
-      // Now complete in the new directory. Set KeyTyped in case the
-      // Up key came from a mapping.
-      s->c = (int)p_wc;
-      KeyTyped = true;
-    }
-  }
+  s->c = wildmenu_process_key(&ccline, s->c, &s->xpc);
 
   // CTRL-\ CTRL-N goes to Normal mode, CTRL-\ e prompts for an expression.
   if (s->c == Ctrl_BSL) {
@@ -3749,16 +3564,6 @@ void cmdline_paste_str(char_u *s, int literally)
   }
 }
 
-/// Delete characters on the command line, from "from" to the current position.
-static void cmdline_del(int from)
-{
-  assert(ccline.cmdpos <= ccline.cmdlen);
-  memmove(ccline.cmdbuff + from, ccline.cmdbuff + ccline.cmdpos,
-          (size_t)ccline.cmdlen - (size_t)ccline.cmdpos + 1);
-  ccline.cmdlen -= ccline.cmdpos - from;
-  ccline.cmdpos = from;
-}
-
 // This function is called when the screen size changes and with incremental
 // search and in other situations where the command line may have been
 // overwritten.