vim-patch:9.1.0770: current command line completion is a bit limited (#30728)

Problem:  current command completion is a bit limited
Solution: Add the shellcmdline completion type and getmdcomplpat()
          function (Ruslan Russkikh).

closes: vim/vim#15823

https://github.com/vim/vim/commit/0407d621bbad020b840ffbbbd25ba023bbc05edd

Co-authored-by: Ruslan Russkikh <dvrussk@yandex.ru>

5 files changed, 61 insertions, 6 deletions

diff --git a/src/nvim/cmdexpand.c b/src/nvim/cmdexpand.c
index 402a891099..b37a1d690f 100644
--- a/src/nvim/cmdexpand.c
+++ b/src/nvim/cmdexpand.c
@@ -119,6 +119,7 @@ static bool cmdline_fuzzy_completion_supported(const expand_T *const xp)
          && xp->xp_context != EXPAND_PACKADD
          && xp->xp_context != EXPAND_RUNTIME
          && xp->xp_context != EXPAND_SHELLCMD
+         && xp->xp_context != EXPAND_SHELLCMDLINE
          && xp->xp_context != EXPAND_TAGS
          && xp->xp_context != EXPAND_TAGS_LISTFILES
          && xp->xp_context != EXPAND_USER_LIST
@@ -1527,7 +1528,8 @@ static void set_context_for_wildcard_arg(exarg_T *eap, const char *arg, bool use
   xp->xp_context = EXPAND_FILES;
 
   // For a shell command more chars need to be escaped.
-  if (usefilter || eap->cmdidx == CMD_bang || eap->cmdidx == CMD_terminal) {
+  if (usefilter || eap->cmdidx == CMD_bang || eap->cmdidx == CMD_terminal
+      || *complp == EXPAND_SHELLCMDLINE) {
 #ifndef BACKSLASH_IN_FILENAME
     xp->xp_shell = true;
 #endif
diff --git a/src/nvim/cmdexpand_defs.h b/src/nvim/cmdexpand_defs.h
index 3369790151..86725eafd6 100644
--- a/src/nvim/cmdexpand_defs.h
+++ b/src/nvim/cmdexpand_defs.h
@@ -106,6 +106,7 @@ enum {
   EXPAND_ARGOPT,
   EXPAND_KEYMAP,
   EXPAND_DIRS_IN_CDPATH,
+  EXPAND_SHELLCMDLINE,
   EXPAND_CHECKHEALTH,
   EXPAND_LUA,
 };
diff --git a/src/nvim/eval.lua b/src/nvim/eval.lua
index 50aaf9e03b..24f986ef4e 100644
--- a/src/nvim/eval.lua
+++ b/src/nvim/eval.lua
@@ -3611,6 +3611,20 @@ M.funcs = {
     returns = 'string',
     signature = 'getcharstr([{expr}])',
   },
+  getcmdcomplpat = {
+    desc = [=[
+      Return completion pattern of the current command-line.
+      Only works when the command line is being edited, thus
+      requires use of |c_CTRL-\_e| or |c_CTRL-R_=|.
+      Also see |getcmdtype()|, |setcmdpos()|, |getcmdline()|,
+      |getcmdprompt()|, |getcmdcompltype()| and |setcmdline()|.
+      Returns an empty string when completion is not defined.
+    ]=],
+    name = 'getcmdcomplpat',
+    params = {},
+    returns = 'string',
+    signature = 'getcmdcomplpat()',
+  },
   getcmdcompltype = {
     desc = [=[
       Return the type of the current command-line completion.
@@ -3618,7 +3632,7 @@ M.funcs = {
       requires use of |c_CTRL-\_e| or |c_CTRL-R_=|.
       See |:command-completion| for the return string.
       Also see |getcmdtype()|, |setcmdpos()|, |getcmdline()|,
-      |getcmdprompt()| and |setcmdline()|.
+      |getcmdprompt()|, |getcmdcomplpat()| and |setcmdline()|.
       Returns an empty string when completion is not defined.
     ]=],
     name = 'getcmdcompltype',
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index ca01a158a3..b58a6b16f1 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -4086,14 +4086,44 @@ static char *get_cmdline_str(void)
   return xstrnsave(p->cmdbuff, (size_t)p->cmdlen);
 }
 
+/// Get the current command-line completion pattern.
+static char *get_cmdline_completion_pattern(void)
+{
+  if (cmdline_star > 0) {
+    return NULL;
+  }
+
+  CmdlineInfo *p = get_ccline_ptr();
+  if (p == NULL || p->xpc == NULL) {
+    return NULL;
+  }
+
+  int xp_context = p->xpc->xp_context;
+  if (xp_context == EXPAND_NOTHING) {
+    set_expand_context(p->xpc);
+    xp_context = p->xpc->xp_context;
+    p->xpc->xp_context = EXPAND_NOTHING;
+  }
+  if (xp_context == EXPAND_UNSUCCESSFUL) {
+    return NULL;
+  }
+
+  char *compl_pat = p->xpc->xp_pattern;
+  if (compl_pat == NULL) {
+    return NULL;
+  }
+
+  return xstrdup(compl_pat);
+}
+
 /// Get the current command-line completion type.
 static char *get_cmdline_completion(void)
 {
   if (cmdline_star > 0) {
     return NULL;
   }
-  CmdlineInfo *p = get_ccline_ptr();
 
+  CmdlineInfo *p = get_ccline_ptr();
   if (p == NULL || p->xpc == NULL) {
     return NULL;
   }
@@ -4123,6 +4153,13 @@ static char *get_cmdline_completion(void)
   return xstrdup(cmd_compl);
 }
 
+/// "getcmdcomplpat()" function
+void f_getcmdcomplpat(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  rettv->v_type = VAR_STRING;
+  rettv->vval.v_string = get_cmdline_completion_pattern();
+}
+
 /// "getcmdcompltype()" function
 void f_getcmdcompltype(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
diff --git a/src/nvim/usercmd.c b/src/nvim/usercmd.c
index d32e0ee319..8404b2bc14 100644
--- a/src/nvim/usercmd.c
+++ b/src/nvim/usercmd.c
@@ -91,6 +91,7 @@ static const char *command_complete[] = {
   [EXPAND_PACKADD] = "packadd",
   [EXPAND_RUNTIME] = "runtime",
   [EXPAND_SHELLCMD] = "shellcmd",
+  [EXPAND_SHELLCMDLINE] = "shellcmdline",
   [EXPAND_SIGN] = "sign",
   [EXPAND_TAGS] = "tag",
   [EXPAND_TAGS_LISTFILES] = "tag_listfiles",
@@ -285,8 +286,7 @@ const char *set_context_in_user_cmdarg(const char *cmd FUNC_ATTR_UNUSED, const c
   }
 
   if (argt & EX_XFILE) {
-    // EX_XFILE: file names are handled above.
-    xp->xp_context = context;
+    // EX_XFILE: file names are handled before this call.
     return NULL;
   }
 
@@ -675,7 +675,8 @@ int parse_compl_arg(const char *value, int vallen, int *complp, uint32_t *argt,
       *complp = i;
       if (i == EXPAND_BUFFERS) {
         *argt |= EX_BUFNAME;
-      } else if (i == EXPAND_DIRECTORIES || i == EXPAND_FILES) {
+      } else if (i == EXPAND_DIRECTORIES || i == EXPAND_FILES
+                 || i == EXPAND_SHELLCMDLINE) {
         *argt |= EX_XFILE;
       }
       break;