patch 8.1.1256: cannot navigate through errors relative to the cursorv8.1.1256

Problem:    Cannot navigate through errors relative to the cursor.
Solution:   Add :cabove, :cbelow, :labove and :lbelow. (Yegappan Lakshmanan,
            closes #4316)

1 files changed, 308 insertions, 3 deletions

diff --git a/src/quickfix.c b/src/quickfix.c
index f90934387..e8c782961 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -177,6 +177,7 @@ static buf_T	*load_dummy_buffer(char_u *fname, char_u *dirname_start, char_u *re
 static void	wipe_dummy_buffer(buf_T *buf, char_u *dirname_start);
 static void	unload_dummy_buffer(buf_T *buf, char_u *dirname_start);
 static qf_info_T *ll_get_or_alloc_list(win_T *);
+static char_u	*e_no_more_items = (char_u *)N_("E553: No more items");
 
 // Quickfix window check helper macro
 #define IS_QF_WINDOW(wp) (bt_quickfix(wp->w_buffer) && wp->w_llist_ref == NULL)
@@ -1494,6 +1495,16 @@ qf_list_empty(qf_list_T *qfl)
 }
 
 /*
+ * Returns TRUE if the specified quickfix/location list is not empty and
+ * has valid entries.
+ */
+    static int
+qf_list_has_valid_entries(qf_list_T *qfl)
+{
+    return !qf_list_empty(qfl) && !qfl->qf_nonevalid;
+}
+
+/*
  * Return a pointer to a list in the specified quickfix stack
  */
     static qf_list_T *
@@ -2700,7 +2711,6 @@ get_nth_valid_entry(
     int			qf_idx = qfl->qf_index;
     qfline_T		*prev_qf_ptr;
     int			prev_index;
-    static char_u	*e_no_more_items = (char_u *)N_("E553: No more items");
     char_u		*err = e_no_more_items;
 
     while (errornr--)
@@ -4886,7 +4896,7 @@ qf_get_cur_valid_idx(exarg_T *eap)
     qfp = qfl->qf_start;
 
     // check if the list has valid errors
-    if (qfl->qf_count <= 0 || qfl->qf_nonevalid)
+    if (!qf_list_has_valid_entries(qfl))
 	return 1;
 
     for (i = 1; i <= qfl->qf_index && qfp!= NULL; i++, qfp = qfp->qf_next)
@@ -4924,7 +4934,7 @@ qf_get_nth_valid_entry(qf_list_T *qfl, int n, int fdo)
     int		prev_fnum = 0;
 
     // check if the list has valid errors
-    if (qfl->qf_count <= 0 || qfl->qf_nonevalid)
+    if (!qf_list_has_valid_entries(qfl))
 	return 1;
 
     eidx = 0;
@@ -5045,6 +5055,301 @@ ex_cnext(exarg_T *eap)
 }
 
 /*
+ * Find the first entry in the quickfix list 'qfl' from buffer 'bnr'.
+ * The index of the entry is stored in 'errornr'.
+ * Returns NULL if an entry is not found.
+ */
+    static qfline_T *
+qf_find_first_entry_in_buf(qf_list_T *qfl, int bnr, int *errornr)
+{
+    qfline_T	*qfp = NULL;
+    int		idx = 0;
+
+    // Find the first entry in this file
+    FOR_ALL_QFL_ITEMS(qfl, qfp, idx)
+	if (qfp->qf_fnum == bnr)
+	    break;
+
+    *errornr = idx;
+    return qfp;
+}
+
+/*
+ * Find the first quickfix entry on the same line as 'entry'. Updates 'errornr'
+ * with the error number for the first entry. Assumes the entries are sorted in
+ * the quickfix list by line number.
+ */
+    static qfline_T *
+qf_find_first_entry_on_line(qfline_T *entry, int *errornr)
+{
+    while (!got_int
+	    && entry->qf_prev != NULL
+	    && entry->qf_fnum == entry->qf_prev->qf_fnum
+	    && entry->qf_lnum == entry->qf_prev->qf_lnum)
+    {
+	entry = entry->qf_prev;
+	--*errornr;
+    }
+
+    return entry;
+}
+
+/*
+ * Find the last quickfix entry on the same line as 'entry'. Updates 'errornr'
+ * with the error number for the last entry. Assumes the entries are sorted in
+ * the quickfix list by line number.
+ */
+    static qfline_T *
+qf_find_last_entry_on_line(qfline_T *entry, int *errornr)
+{
+    while (!got_int &&
+	    entry->qf_next != NULL
+	    && entry->qf_fnum == entry->qf_next->qf_fnum
+	    && entry->qf_lnum == entry->qf_next->qf_lnum)
+    {
+	entry = entry->qf_next;
+	++*errornr;
+    }
+
+    return entry;
+}
+
+/*
+ * Find the first quickfix entry below line 'lnum' in buffer 'bnr'.
+ * 'qfp' points to the very first entry in the buffer and 'errornr' is the
+ * index of the very first entry in the quickfix list.
+ * Returns NULL if an entry is not found after 'lnum'.
+ */
+    static qfline_T *
+qf_find_entry_on_next_line(
+	int		bnr,
+	linenr_T	lnum,
+	qfline_T	*qfp,
+	int		*errornr)
+{
+    if (qfp->qf_lnum > lnum)
+	// First entry is after line 'lnum'
+	return qfp;
+
+    // Find the entry just before or at the line 'lnum'
+    while (qfp->qf_next != NULL
+	    && qfp->qf_next->qf_fnum == bnr
+	    && qfp->qf_next->qf_lnum <= lnum)
+    {
+	qfp = qfp->qf_next;
+	++*errornr;
+    }
+
+    if (qfp->qf_next == NULL || qfp->qf_next->qf_fnum != bnr)
+	// No entries found after 'lnum'
+	return NULL;
+
+    // Use the entry just after line 'lnum'
+    qfp = qfp->qf_next;
+    ++*errornr;
+
+    return qfp;
+}
+
+/*
+ * Find the first quickfix entry before line 'lnum' in buffer 'bnr'.
+ * 'qfp' points to the very first entry in the buffer and 'errornr' is the
+ * index of the very first entry in the quickfix list.
+ * Returns NULL if an entry is not found before 'lnum'.
+ */
+    static qfline_T *
+qf_find_entry_on_prev_line(
+	int		bnr,
+	linenr_T	lnum,
+	qfline_T	*qfp,
+	int		*errornr)
+{
+    // Find the entry just before the line 'lnum'
+    while (qfp->qf_next != NULL
+	    && qfp->qf_next->qf_fnum == bnr
+	    && qfp->qf_next->qf_lnum < lnum)
+    {
+	qfp = qfp->qf_next;
+	++*errornr;
+    }
+
+    if (qfp->qf_lnum >= lnum)	// entry is after 'lnum'
+	return NULL;
+
+    // If multiple entries are on the same line, then use the first entry
+    qfp = qf_find_first_entry_on_line(qfp, errornr);
+
+    return qfp;
+}
+
+/*
+ * Find a quickfix entry in 'qfl' closest to line 'lnum' in buffer 'bnr' in
+ * the direction 'dir'.
+ */
+    static qfline_T *
+qf_find_closest_entry(
+	qf_list_T	*qfl,
+	int		bnr,
+	linenr_T	lnum,
+	int		dir,
+	int		*errornr)
+{
+    qfline_T	*qfp;
+
+    *errornr = 0;
+
+    // Find the first entry in this file
+    qfp = qf_find_first_entry_in_buf(qfl, bnr, errornr);
+    if (qfp == NULL)
+	return NULL;		// no entry in this file
+
+    if (dir == FORWARD)
+	qfp = qf_find_entry_on_next_line(bnr, lnum, qfp, errornr);
+    else
+	qfp = qf_find_entry_on_prev_line(bnr, lnum, qfp, errornr);
+
+    return qfp;
+}
+
+/*
+ * Get the nth quickfix entry below the specified entry treating multiple
+ * entries on a single line as one. Searches forward in the list.
+ */
+    static qfline_T *
+qf_get_nth_below_entry(qfline_T *entry, int *errornr, int n)
+{
+    while (n-- > 0 && !got_int)
+    {
+	qfline_T	*first_entry = entry;
+	int		first_errornr = *errornr;
+
+	// Treat all the entries on the same line in this file as one
+	entry = qf_find_last_entry_on_line(entry, errornr);
+
+	if (entry->qf_next == NULL
+		|| entry->qf_next->qf_fnum != entry->qf_fnum)
+	{
+	    // If multiple entries are on the same line, then use the first
+	    // entry
+	    entry = first_entry;
+	    *errornr = first_errornr;
+	    break;
+	}
+
+	entry = entry->qf_next;
+	++*errornr;
+    }
+
+    return entry;
+}
+
+/*
+ * Get the nth quickfix entry above the specified entry treating multiple
+ * entries on a single line as one. Searches backwards in the list.
+ */
+    static qfline_T *
+qf_get_nth_above_entry(qfline_T *entry, int *errornr, int n)
+{
+    while (n-- > 0 && !got_int)
+    {
+	if (entry->qf_prev == NULL
+		|| entry->qf_prev->qf_fnum != entry->qf_fnum)
+	    break;
+
+	entry = entry->qf_prev;
+	--*errornr;
+
+	// If multiple entries are on the same line, then use the first entry
+	entry = qf_find_first_entry_on_line(entry, errornr);
+    }
+
+    return entry;
+}
+
+/*
+ * Find the n'th quickfix entry adjacent to line 'lnum' in buffer 'bnr' in the
+ * specified direction.
+ * Returns the error number in the quickfix list or 0 if an entry is not found.
+ */
+    static int
+qf_find_nth_adj_entry(qf_list_T *qfl, int bnr, linenr_T lnum, int n, int dir)
+{
+    qfline_T	*adj_entry;
+    int		errornr;
+
+    // Find an entry closest to the specified line
+    adj_entry = qf_find_closest_entry(qfl, bnr, lnum, dir, &errornr);
+    if (adj_entry == NULL)
+	return 0;
+
+    if (--n > 0)
+    {
+	// Go to the n'th entry in the current buffer
+	if (dir == FORWARD)
+	    adj_entry = qf_get_nth_below_entry(adj_entry, &errornr, n);
+	else
+	    adj_entry = qf_get_nth_above_entry(adj_entry, &errornr, n);
+    }
+
+    return errornr;
+}
+
+/*
+ * Jump to a quickfix entry in the current file nearest to the current line.
+ * ":cabove", ":cbelow", ":labove" and ":lbelow" commands
+ */
+    void
+ex_cbelow(exarg_T *eap)
+{
+    qf_info_T	*qi;
+    qf_list_T	*qfl;
+    int		dir;
+    int		buf_has_flag;
+    int		errornr = 0;
+
+    if (eap->addr_count > 0 && eap->line2 <= 0)
+    {
+	emsg(_(e_invrange));
+	return;
+    }
+
+    // Check whether the current buffer has any quickfix entries
+    if (eap->cmdidx == CMD_cabove || eap->cmdidx == CMD_cbelow)
+	buf_has_flag = BUF_HAS_QF_ENTRY;
+    else
+	buf_has_flag = BUF_HAS_LL_ENTRY;
+    if (!(curbuf->b_has_qf_entry & buf_has_flag))
+    {
+	emsg(_(e_quickfix));
+	return;
+    }
+
+    if ((qi = qf_cmd_get_stack(eap, TRUE)) == NULL)
+	return;
+
+    qfl = qf_get_curlist(qi);
+    // check if the list has valid errors
+    if (!qf_list_has_valid_entries(qfl))
+    {
+	emsg(_(e_quickfix));
+	return;
+    }
+
+    if (eap->cmdidx == CMD_cbelow || eap->cmdidx == CMD_lbelow)
+	dir = FORWARD;
+    else
+	dir = BACKWARD;
+
+    errornr = qf_find_nth_adj_entry(qfl, curbuf->b_fnum, curwin->w_cursor.lnum,
+	    eap->addr_count > 0 ? eap->line2 : 0, dir);
+
+    if (errornr > 0)
+	qf_jump(qi, 0, errornr, FALSE);
+    else
+	emsg(_(e_no_more_items));
+}
+
+/*
  * Return the autocmd name for the :cfile Ex commands
  */
     static char_u *