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)

2 files changed, 34 insertions, 0 deletions

diff --git a/runtime/doc/index.txt b/runtime/doc/index.txt
index c95de5b7b..719290556 100644
--- a/runtime/doc/index.txt
+++ b/runtime/doc/index.txt
@@ -1188,11 +1188,13 @@ tag		command		action ~
 |:cNfile|	:cNf[ile]	go to last error in previous file
 |:cabbrev|	:ca[bbrev]	like ":abbreviate" but for Command-line mode
 |:cabclear|	:cabc[lear]	clear all abbreviations for Command-line mode
+|:cabove|	:cabo[ve]	go to error above current line
 |:caddbuffer|	:cad[dbuffer]	add errors from buffer
 |:caddexpr|	:cadde[xpr]	add errors from expr
 |:caddfile|	:caddf[ile]	add error message to current quickfix list
 |:call|		:cal[l]		call a function
 |:catch|	:cat[ch]	part of a :try command
+|:cbelow|	:cbe[low]	got to error below current line
 |:cbottom|	:cbo[ttom]	scroll to the bottom of the quickfix window
 |:cbuffer|	:cb[uffer]	parse error messages and jump to first error
 |:cc|		:cc		go to specific error
@@ -1350,12 +1352,14 @@ tag		command		action ~
 |:lNext|	:lN[ext]	go to previous entry in location list
 |:lNfile|	:lNf[ile]	go to last entry in previous file
 |:list|		:l[ist]		print lines
+|:labove|	:lab[ove]	go to location above current line
 |:laddexpr|	:lad[dexpr]	add locations from expr
 |:laddbuffer|	:laddb[uffer]	add locations from buffer
 |:laddfile|	:laddf[ile]	add locations to current location list
 |:last|		:la[st]		go to the last file in the argument list
 |:language|	:lan[guage]	set the language (locale)
 |:later|	:lat[er]	go to newer change, redo
+|:lbelow|	:lbe[low]	go to location below current line
 |:lbottom|	:lbo[ttom]	scroll to the bottom of the location window
 |:lbuffer|	:lb[uffer]	parse locations and jump to first location
 |:lcd|		:lc[d]		change directory locally
diff --git a/runtime/doc/quickfix.txt b/runtime/doc/quickfix.txt
index 0ceb231b8..6f17b77d4 100644
--- a/runtime/doc/quickfix.txt
+++ b/runtime/doc/quickfix.txt
@@ -123,6 +123,36 @@ processing a quickfix or location list command, it will be aborted.
 			list for the current window is used instead of the
 			quickfix list.
 
+							*:cabo* *:cabove*
+:[count]cabo[ve]	Go to the [count] error above the current line in the
+			current buffer.  If [count] is omitted, then 1 is
+			used.  If there are no errors, then an error message
+			is displayed.  Assumes that the entries in a quickfix
+			list are sorted by their buffer number and line
+			number. If there are multiple errors on the same line,
+			then only the first entry is used.  If [count] exceeds
+			the number of entries above the current line, then the
+			first error in the file is selected.
+
+							*:lab* *:labove*
+:[count]lab[ove]	Same as ":cabove", except the location list for the
+			current window is used instead of the quickfix list.
+
+							*:cbe* *:cbelow*
+:[count]cbe[low]	Go to the [count] error below the current line in the
+			current buffer.  If [count] is omitted, then 1 is
+			used.  If there are no errors, then an error message
+			is displayed.  Assumes that the entries in a quickfix
+			list are sorted by their buffer number and line
+			number.  If there are multiple errors on the same
+			line, then only the first entry is used.  If [count]
+			exceeds the number of entries below the current line,
+			then the last error in the file is selected.
+
+							*:lbe* *:lbelow*
+:[count]lbe[low]	Same as ":cbelow", except the location list for the
+			current window is used instead of the quickfix list.
+
 							*:cnf* *:cnfile*
 :[count]cnf[ile][!]	Display the first error in the [count] next file in
 			the list that includes a file name.  If there are no