vim-patch:8.1.1112: duplicate code in quickfix file

Problem:    Duplicate code in quickfix file.
Solution:   Move code into functions. (Yegappan Lakshmanan, closes vim/vim#4207)
https://github.com/vim/vim/commit/87f59b09ea4b9af2712598374a6044f5fa1b54a4

2 files changed, 96 insertions, 92 deletions

diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index c45d60cb3f..731817a2b4 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -1899,9 +1899,49 @@ static qf_info_T *ll_get_or_alloc_list(win_T *wp)
   return wp->w_llist;
 }
 
+// Get the quickfix/location list stack to use for the specified Ex command.
+// For a location list command, returns the stack for the current window.  If
+// the location list is not found, then returns NULL and prints an error
+// message if 'print_emsg' is TRUE.
+static qf_info_T * qf_cmd_get_stack(exarg_T *eap, int print_emsg)
+{
+  qf_info_T *qi = &ql_info;
+
+  if (is_loclist_cmd(eap->cmdidx)) {
+    qi = GET_LOC_LIST(curwin);
+    if (qi == NULL) {
+      if (print_emsg) {
+        EMSG(_(e_loclist));
+      }
+      return NULL;
+    }
+  }
+
+  return qi;
+}
+
+// Get the quickfix/location list stack to use for the specified Ex command.
+// For a location list command, returns the stack for the current window.
+// If the location list is not present, then allocates a new one.
+// Returns NULL if the allocation fails.  For a location list command, sets
+// 'pwinp' to curwin.
+static qf_info_T * qf_cmd_get_or_alloc_stack(exarg_T *eap, win_T **pwinp)
+{
+  qf_info_T *qi = &ql_info;
+
+  if (is_loclist_cmd(eap->cmdidx)) {
+    qi = ll_get_or_alloc_list(curwin);
+    if (qi == NULL) {
+      return NULL;
+    }
+    *pwinp = curwin;
+  }
+
+  return qi;
+}
+
 // Copy location list entries from 'from_qfl' to 'to_qfl'.
-static int copy_loclist_entries(const qf_list_T *from_qfl,
-                                qf_list_T *to_qfl)
+static int copy_loclist_entries(const qf_list_T *from_qfl, qf_list_T *to_qfl)
   FUNC_ATTR_NONNULL_ALL
 {
   int i;
@@ -3009,14 +3049,10 @@ void qf_list(exarg_T *eap)
   char_u      *arg = eap->arg;
   int         all = eap->forceit;     // if not :cl!, only show
                                       // recognised errors
-  qf_info_T   *qi = &ql_info;
+  qf_info_T *qi;
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = GET_LOC_LIST(curwin);
-    if (qi == NULL) {
-      EMSG(_(e_loclist));
-      return;
-    }
+  if ((qi = qf_cmd_get_stack(eap, true)) == NULL) {
+    return;
   }
 
   if (qf_stack_empty(qi) || qf_list_empty(qf_get_curlist(qi))) {
@@ -3135,15 +3171,11 @@ static void qf_msg(qf_info_T *qi, int which, char *lead)
  */
 void qf_age(exarg_T *eap)
 {
-  qf_info_T   *qi = &ql_info;
+  qf_info_T *qi;
   int count;
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = GET_LOC_LIST(curwin);
-    if (qi == NULL) {
-      EMSG(_(e_loclist));
-      return;
-    }
+  if ((qi = qf_cmd_get_stack(eap, true)) == NULL) {
+    return;
   }
 
   if (eap->addr_count != 0) {
@@ -3174,12 +3206,9 @@ void qf_age(exarg_T *eap)
 /// Display the information about all the quickfix/location lists in the stack.
 void qf_history(exarg_T *eap)
 {
-  qf_info_T *qi = &ql_info;
+  qf_info_T *qi = qf_cmd_get_stack(eap, false);
   int i;
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = GET_LOC_LIST(curwin);
-  }
   if (qf_stack_empty(qi) || qf_list_empty(qf_get_curlist(qi))) {
     MSG(_("No entries"));
   } else {
@@ -3374,14 +3403,12 @@ void qf_view_result(bool split)
  */
 void ex_cwindow(exarg_T *eap)
 {
-  qf_info_T   *qi = &ql_info;
+  qf_info_T   *qi;
   qf_list_T   *qfl;
   win_T       *win;
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = GET_LOC_LIST(curwin);
-    if (qi == NULL)
-      return;
+  if ((qi = qf_cmd_get_stack(eap, true)) == NULL) {
+    return;
   }
 
   qfl = qf_get_curlist(qi);
@@ -3411,13 +3438,11 @@ void ex_cwindow(exarg_T *eap)
  */
 void ex_cclose(exarg_T *eap)
 {
-  win_T       *win = NULL;
-  qf_info_T   *qi = &ql_info;
+  win_T *win = NULL;
+  qf_info_T *qi;
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = GET_LOC_LIST(curwin);
-    if (qi == NULL)
-      return;
+  if ((qi = qf_cmd_get_stack(eap, false)) == NULL) {
+    return;
   }
 
   /* Find existing quickfix window and close it. */
@@ -3533,18 +3558,14 @@ static void qf_set_title_var(qf_list_T *qfl)
  */
 void ex_copen(exarg_T *eap)
 {
-  qf_info_T   *qi = &ql_info;
+  qf_info_T   *qi;
   qf_list_T   *qfl;
   int height;
   int status = FAIL;
   int lnum;
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = GET_LOC_LIST(curwin);
-    if (qi == NULL) {
-      EMSG(_(e_loclist));
-      return;
-    }
+  if ((qi = qf_cmd_get_stack(eap, true)) == NULL) {
+    return;
   }
 
   incr_quickfix_busy();
@@ -3607,14 +3628,10 @@ static void qf_win_goto(win_T *win, linenr_T lnum)
 // :cbottom/:lbottom command.
 void ex_cbottom(exarg_T *eap)
 {
-  qf_info_T *qi = &ql_info;
+  qf_info_T *qi;
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = GET_LOC_LIST(curwin);
-    if (qi == NULL) {
-      EMSG(_(e_loclist));
-      return;
-    }
+  if ((qi = qf_cmd_get_stack(eap, true)) == NULL) {
+    return;
   }
 
   win_T *win = qf_find_win(qi);
@@ -4162,14 +4179,11 @@ static char_u *get_mef_name(void)
 size_t qf_get_size(exarg_T *eap)
   FUNC_ATTR_NONNULL_ALL
 {
-  qf_info_T *qi = &ql_info;
+  qf_info_T *qi;
   qf_list_T *qfl;
-  if (is_loclist_cmd(eap->cmdidx)) {
-    // Location list.
-    qi = GET_LOC_LIST(curwin);
-    if (qi == NULL) {
-      return 0;
-    }
+
+  if ((qi = qf_cmd_get_stack(eap, false)) == NULL) {
+    return 0;
   }
 
   int prev_fnum = 0;
@@ -4201,14 +4215,10 @@ size_t qf_get_size(exarg_T *eap)
 size_t qf_get_cur_idx(exarg_T *eap)
   FUNC_ATTR_NONNULL_ALL
 {
-  qf_info_T *qi = &ql_info;
+  qf_info_T *qi;
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    // Location list.
-    qi = GET_LOC_LIST(curwin);
-    if (qi == NULL) {
-      return 0;
-    }
+  if ((qi = qf_cmd_get_stack(eap, false)) == NULL) {
+    return 0;
   }
 
   assert(qf_get_curlist(qi)->qf_index >= 0);
@@ -4221,14 +4231,10 @@ size_t qf_get_cur_idx(exarg_T *eap)
 int qf_get_cur_valid_idx(exarg_T *eap)
   FUNC_ATTR_NONNULL_ALL
 {
-  qf_info_T *qi = &ql_info;
+  qf_info_T *qi;
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    // Location list.
-    qi = GET_LOC_LIST(curwin);
-    if (qi == NULL) {
-      return 1;
-    }
+  if ((qi = qf_cmd_get_stack(eap, false)) == NULL) {
+    return 1;
   }
 
   qf_list_T *qfl = qf_get_curlist(qi);
@@ -4310,14 +4316,10 @@ static size_t qf_get_nth_valid_entry(qf_list_T *qfl, size_t n, int fdo)
  */
 void ex_cc(exarg_T *eap)
 {
-  qf_info_T   *qi = &ql_info;
+  qf_info_T   *qi;
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = GET_LOC_LIST(curwin);
-    if (qi == NULL) {
-      EMSG(_(e_loclist));
-      return;
-    }
+  if ((qi = qf_cmd_get_stack(eap, true)) == NULL) {
+    return;
   }
 
   int errornr;
@@ -4369,14 +4371,10 @@ void ex_cc(exarg_T *eap)
  */
 void ex_cnext(exarg_T *eap)
 {
-  qf_info_T   *qi = &ql_info;
+  qf_info_T   *qi;
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = GET_LOC_LIST(curwin);
-    if (qi == NULL) {
-      EMSG(_(e_loclist));
-      return;
-    }
+  if ((qi = qf_cmd_get_stack(eap, true)) == NULL) {
+    return;
   }
 
   int errornr;
@@ -4695,7 +4693,7 @@ void ex_vimgrep(exarg_T *eap)
   char_u      *s;
   char_u      *p;
   int fi;
-  qf_info_T   *qi = &ql_info;
+  qf_info_T   *qi;
   qf_list_T   *qfl;
   win_T *wp = NULL;
   buf_T       *buf;
@@ -4721,9 +4719,9 @@ void ex_vimgrep(exarg_T *eap)
     }
   }
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = ll_get_or_alloc_list(curwin);
-    wp = curwin;
+  qi = qf_cmd_get_or_alloc_stack(eap, &wp);
+  if (qi == NULL) {
+    return;
   }
 
   if (eap->addr_count > 0)
@@ -6031,7 +6029,7 @@ static int cbuffer_process_args(exarg_T *eap,
 void ex_cbuffer(exarg_T *eap)
 {
   buf_T *buf = NULL;
-  qf_info_T *qi = &ql_info;
+  qf_info_T *qi;
   char_u *au_name = NULL;
   win_T *wp = NULL;
   char_u *qf_title;
@@ -6047,9 +6045,9 @@ void ex_cbuffer(exarg_T *eap)
   }
 
   // Must come after autocommands.
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = ll_get_or_alloc_list(curwin);
-    wp = curwin;
+  qi = qf_cmd_get_or_alloc_stack(eap, &wp);
+  if (qi == NULL) {
+    return;
   }
 
   if (cbuffer_process_args(eap, &buf, &line1, &line2) == FAIL) {
@@ -6121,7 +6119,7 @@ static char_u * cexpr_get_auname(cmdidx_T cmdidx)
  */
 void ex_cexpr(exarg_T *eap)
 {
-  qf_info_T *qi = &ql_info;
+  qf_info_T *qi;
   char_u *au_name = NULL;
   win_T *wp = NULL;
 
@@ -6133,9 +6131,9 @@ void ex_cexpr(exarg_T *eap)
     }
   }
 
-  if (is_loclist_cmd(eap->cmdidx)) {
-    qi = ll_get_or_alloc_list(curwin);
-    wp = curwin;
+  qi = qf_cmd_get_or_alloc_stack(eap, &wp);
+  if (qi == NULL) {
+    return;
   }
 
   /* Evaluate the expression.  When the result is a string or a list we can
diff --git a/src/nvim/testdir/test_quickfix.vim b/src/nvim/testdir/test_quickfix.vim
index 26b43d9818..131e9d72e3 100644
--- a/src/nvim/testdir/test_quickfix.vim
+++ b/src/nvim/testdir/test_quickfix.vim
@@ -163,6 +163,12 @@ endfunc
 func XageTests(cchar)
   call s:setup_commands(a:cchar)
 
+  if a:cchar == 'l'
+    " No location list for the current window
+    call assert_fails('lolder', 'E776:')
+    call assert_fails('lnewer', 'E776:')
+  endif
+
   let list = [{'bufnr': bufnr('%'), 'lnum': 1}]
   call g:Xsetlist(list)