fix(editline): no newline if cursor within range on last line (#131)

If the cursor was at the very end of a string, but not past the
width, it would still insert an extra line when formatting.

Author: Tieske

spec/09-editline-format_spec.lua

@@ -640,6 +640,43 @@ describe("EditLine:", function()
         end)
 
 
+        it("doesn't add new line if cursor is at the end of a non-oversized last line", function()
+          -- single line
+          line = EditLine("some test data"):goto_end()
+          assert.are.same({
+            {
+              'some test data|'
+            },
+            1,
+            15,
+          }, {testwrap({
+            width = 20,
+            first_width = 20,
+            wordwrap = false,
+            pad = false,
+            pad_last = false
+          })})
+
+          -- again with multiple lines
+          line = EditLine("sometestda"):goto_end()
+          assert.are.same({
+            {
+              'some|',
+              'test|',
+              'da|',
+            },
+            3,
+            3,
+          }, {testwrap({
+            width = 4,
+            first_width = 4,
+            wordwrap = false,
+            pad = false,
+            pad_last = false
+          })})
+        end)
+
+
         it("doesn't add the extra newline if set to do so", function()
           line = EditLine("sometestdata"):goto_end()
           assert.are.same({
@@ -935,6 +972,43 @@ describe("EditLine:", function()
         end)
 
 
+        it("doesn't add new line if cursor is at the end of a non-oversized last line", function()
+          -- single line
+          line = EditLine("some test data"):goto_end()
+          assert.are.same({
+            {
+              'some test data|'
+            },
+            1,
+            15,
+          }, {testwrap({
+            width = 60,
+            first_width = 20,
+            wordwrap = true,
+            pad = false,
+            pad_last = false
+          })})
+
+          -- again with multiple lines
+          line = EditLine("somexx testxx data"):goto_end()
+          assert.are.same({
+            {
+              'somexx |',
+              'testxx |',
+              'data|',
+            },
+            3,
+            5,
+          }, {testwrap({
+            width = 8,
+            first_width = 8,
+            wordwrap = true,
+            pad = false,
+            pad_last = false
+          })})
+        end)
+
+
         it("doesn't add the extra newline if set to do so", function()
           line = EditLine("some testdata"):goto_end()
           assert.are.same({

src/terminal/editline.lua

@@ -603,18 +603,40 @@ do
       target_size = width -- update target size after first-line
     end
 
-    -- add extra line holding cursor, if cursor is at the end of the last line at exact length
-    -- (so the cursor is beyond the width set, and is the only thing on the next line)
+    -- did we set the cursor position? (not set if the cursor is at the very end)
     if cur_line == nil then
-      if no_new_cursor_line then
-        -- no new line, so cursor is at the end of the last line, beyond the width
-        cur_line = #lines
-        cur_col = width + 1
+      -- if  the last line isn't at full length, then we have the cursor in a regular position
+      -- at the end of that line
+      if #lines == 1 then
+        local l = lines[1]:len_col()
+        if l < first_width then
+          -- cursor is on a first-line, on a regular position
+          cur_line = 1
+          cur_col = l + 1
+        end
       else
-        -- add an empty new line just to hold the cursor
-        cur_line = #lines + 1
-        lines[cur_line] = EditLine("")
-        cur_col = 1
+        local l = lines[#lines]:len_col()
+        if l < width then
+          -- cursor is on a second or later line, on a regular position
+          cur_line = #lines
+          cur_col = l + 1
+        end
+      end
+
+      -- wasn't on a regular position on the line, so past the end.
+      -- add extra line holding cursor, if cursor is at the end of the last line at exact length
+      -- (so the cursor is beyond the width set, and is the only thing on the next line)
+      if cur_line == nil then
+        if no_new_cursor_line then
+          -- no new line, so cursor is at the end of the last line, beyond the width
+          cur_line = #lines
+          cur_col = width + 1
+        else
+          -- add an empty new line just to hold the cursor
+          cur_line = #lines + 1
+          lines[cur_line] = EditLine("")
+          cur_col = 1
+        end
       end
     end