Improve comment-line command

rc/core/comment.kak

@@ -150,16 +150,32 @@ define-command comment-line -docstring '(un)comment selected lines using line co
         try %{
             # Keep non-empty lines
             execute-keys <a-K>\A\s*\z<ret>
+        } catch %{
+        }
+
+        try %{
+            set-register / "\A\Q%opt{comment_line}\E\h?"
 
             try %{
-                # Select the comment characters and remove them
-                set-register / "\A\Q%opt{comment_line}\E\h*"
-                execute-keys s<ret>d
-            } catch %{
-                # Comment the line
+                # See if there are any uncommented lines in the selection
+                execute-keys -draft <a-K><ret>
+
+                # There are uncommented lines, so comment everything
                 set-register '"' "%opt{comment_line} "
+                align-cursors-left
                 execute-keys P
+            } catch %{
+                # All lines were commented, so uncomment everything
+                execute-keys s<ret>d
             }
         }
     }
 }
+
+define-command align-cursors-left -docstring 'set all cursor (and anchor) columns to the column of the leftmost cursor' %{
+    %sh{
+        leftmost_column=$(echo "$kak_selections_desc" | tr ':' '\n' | cut -d',' -f1 | cut -d'.' -f2 | sort -n | head -n1)
+        aligned_selections=$(echo "$kak_selections_desc" | sed "s/\.[0-9]\+,/.$leftmost_column,/g")
+        echo "select $aligned_selections"
+    }
+}

test/indent/comment/comment-multiple-lines-indented/cmd

@@ -0,0 +1 @@
+jXXX:comment-line<ret>

test/indent/comment/comment-multiple-lines-indented/in

@@ -0,0 +1,4 @@
+a:
+    b: 1
+
+    c: 2

test/indent/comment/comment-multiple-lines-indented/out

@@ -0,0 +1,4 @@
+a:
+    # b: 1
+
+    # c: 2

test/indent/comment/comment-multiple-lines-indented/rc

@@ -0,0 +1,4 @@
+source "%val{runtime}/colors/default.kak"
+source "%val{runtime}/rc/base/yaml.kak"
+source "%val{runtime}/rc/core/comment.kak"
+set buffer filetype yaml

test/indent/comment/comment-multiple-lines-unindented/cmd

@@ -0,0 +1 @@
+%:comment-line<ret>

test/indent/comment/comment-multiple-lines-unindented/in

@@ -0,0 +1,4 @@
+a:
+    b: 1
+
+    c: 2

test/indent/comment/comment-multiple-lines-unindented/out

@@ -0,0 +1,4 @@
+# a:
+#     b: 1
+
+#     c: 2

test/indent/comment/comment-multiple-lines-unindented/rc

@@ -0,0 +1,4 @@
+source "%val{runtime}/colors/default.kak"
+source "%val{runtime}/rc/base/yaml.kak"
+source "%val{runtime}/rc/core/comment.kak"
+set buffer filetype yaml

test/indent/comment/comment-multiple-lines-when-partially-commented/cmd

@@ -0,0 +1 @@
+%:comment-line<ret>

test/indent/comment/comment-multiple-lines-when-partially-commented/in

@@ -0,0 +1,3 @@
+a:
+    # b: 1
+    c: 2

test/indent/comment/comment-multiple-lines-when-partially-commented/out

@@ -0,0 +1,3 @@
+# a:
+#     # b: 1
+#     c: 2

test/indent/comment/comment-multiple-lines-when-partially-commented/rc

@@ -0,0 +1,4 @@
+source "%val{runtime}/colors/default.kak"
+source "%val{runtime}/rc/base/yaml.kak"
+source "%val{runtime}/rc/core/comment.kak"
+set buffer filetype yaml