diff --git a/src/cmdexpand.c b/src/cmdexpand.c
index b59610c..20f3069 100644
--- a/src/cmdexpand.c
+++ b/src/cmdexpand.c
@@ -113,9 +113,10 @@
 	for (int i = 0; i < numfiles; ++i)
 	{
 	    // for ":set path=" we need to escape spaces twice
-	    if (xp->xp_backslash == XP_BS_THREE)
+	    if (xp->xp_backslash & XP_BS_THREE)
 	    {
-		p = vim_strsave_escaped(files[i], (char_u *)" ");
+		char *pat = (xp->xp_backslash & XP_BS_COMMA) ?  " ," : " ";
+		p = vim_strsave_escaped(files[i], (char_u *)pat);
 		if (p != NULL)
 		{
 		    vim_free(files[i]);
@@ -130,6 +131,18 @@
 #endif
 		}
 	    }
+	    else if (xp->xp_backslash & XP_BS_COMMA)
+	    {
+		if (vim_strchr(files[i], ',') != NULL)
+		{
+		    p = vim_strsave_escaped(files[i], (char_u *)",");
+		    if (p != NULL)
+		    {
+			vim_free(files[i]);
+			files[i] = p;
+		    }
+		}
+	    }
 #ifdef BACKSLASH_IN_FILENAME
 	    p = vim_strsave_fnameescape(files[i], vse_what);
 #else
@@ -2730,14 +2743,23 @@
 	for (i = 0; pat[i]; ++i)
 	    if (pat[i] == '\\')
 	    {
-		if (xp->xp_backslash == XP_BS_THREE
+		if (xp->xp_backslash & XP_BS_THREE
 			&& pat[i + 1] == '\\'
 			&& pat[i + 2] == '\\'
 			&& pat[i + 3] == ' ')
 		    STRMOVE(pat + i, pat + i + 3);
-		if (xp->xp_backslash == XP_BS_ONE
+		else if (xp->xp_backslash & XP_BS_ONE
 			&& pat[i + 1] == ' ')
 		    STRMOVE(pat + i, pat + i + 1);
+		else if ((xp->xp_backslash & XP_BS_COMMA)
+			&& pat[i + 1] == '\\'
+			&& pat[i + 2] == ',')
+		    STRMOVE(pat + i, pat + i + 2);
+#ifdef BACKSLASH_IN_FILENAME
+		else if ((xp->xp_backslash & XP_BS_COMMA)
+			&& pat[i + 1] == ',')
+		    STRMOVE(pat + i, pat + i + 1);
+#endif
 	    }
     }
 
diff --git a/src/option.c b/src/option.c
index ae2ca3a..b1e70c6 100644
--- a/src/option.c
+++ b/src/option.c
@@ -7451,6 +7451,8 @@
 	    else
 		xp->xp_backslash = XP_BS_ONE;
 	}
+	if (flags & P_COMMA)
+	    xp->xp_backslash |= XP_BS_COMMA;
     }
 
     // For an option that is a list of file names, or comma/colon-separated
@@ -7469,8 +7471,12 @@
 		s = p;
 		while (s > xp->xp_pattern && *(s - 1) == '\\')
 		    --s;
-		if ((*p == ' ' && (xp->xp_backslash == XP_BS_THREE && (p - s) < 3))
-			|| (*p == ',' && (flags & P_COMMA) && ((p - s) % 1) == 0)
+		if ((*p == ' ' && ((xp->xp_backslash & XP_BS_THREE) && (p - s) < 3))
+#if defined(BACKSLASH_IN_FILENAME)
+			|| (*p == ',' && (flags & P_COMMA) && (p - s) < 1)
+#else
+			|| (*p == ',' && (flags & P_COMMA) && (p - s) < 2)
+#endif
 			|| (*p == ':' && (flags & P_COLON)))
 		{
 		    xp->xp_pattern = p + 1;
diff --git a/src/structs.h b/src/structs.h
index ee68884..c7cf412 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -631,8 +631,9 @@
  * values for xp_backslash
  */
 #define XP_BS_NONE	0	// nothing special for backslashes
-#define XP_BS_ONE	1	// uses one backslash before a space
-#define XP_BS_THREE	2	// uses three backslashes before a space
+#define XP_BS_ONE	0x1	// uses one backslash before a space
+#define XP_BS_THREE	0x2	// uses three backslashes before a space
+#define XP_BS_COMMA	0x4	// commas need to be escaped with a backslash
 
 /*
  * Variables shared between getcmdline(), redrawcmdline() and others.
diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index a54c507..e79fa72 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -1257,13 +1257,71 @@
   mapclear
   delcom MyCmd
 
+  " Prepare for path completion
+  call mkdir('Xa b c', 'D')
+  defer delete('Xcomma,foobar.txt')
+  call writefile([], 'Xcomma,foobar.txt')
+
   " completion for :set path= with multiple backslashes
-  call feedkeys(":set path=a\\\\\\ b\<C-A>\<C-B>\"\<CR>", 'xt')
-  call assert_equal('"set path=a\\\ b', @:)
+  call feedkeys(':set path=Xa\\\ b' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"set path=Xa\\\ b\\\ c/', @:)
+  set path&
 
   " completion for :set dir= with a backslash
-  call feedkeys(":set dir=a\\ b\<C-A>\<C-B>\"\<CR>", 'xt')
-  call assert_equal('"set dir=a\ b', @:)
+  call feedkeys(':set dir=Xa\ b' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"set dir=Xa\ b\ c/', @:)
+  set dir&
+
+  " completion for :set tags= / set dictionary= with escaped commas
+  if has('win32')
+    " In Windows backslashes are rounded up, so both '\,' and '\\,' escape to
+    " '\,'
+    call feedkeys(':set dictionary=Xcomma\,foo' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+    call assert_equal('"set dictionary=Xcomma\,foobar.txt', @:)
+
+    call feedkeys(':set tags=Xcomma\\,foo' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+    call assert_equal('"set tags=Xcomma\,foobar.txt', @:)
+
+    call feedkeys(':set tags=Xcomma\\\,foo' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+    call assert_equal('"set tags=Xcomma\\\,foo', @:) " Didn't find a match
+
+    " completion for :set dictionary= with escaped commas (same behavior, but
+    " different internal code path from 'set tags=' for escaping the output)
+    call feedkeys(':set tags=Xcomma\\,foo' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+    call assert_equal('"set tags=Xcomma\,foobar.txt', @:)
+  else
+    " In other platforms, backslashes are rounded down (since '\,' itself will
+    " be escaped into ','). As a result '\\,' and '\\\,' escape to '\,'.
+    call feedkeys(':set tags=Xcomma\,foo' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+    call assert_equal('"set tags=Xcomma\,foo', @:) " Didn't find a match
+
+    call feedkeys(':set tags=Xcomma\\,foo' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+    call assert_equal('"set tags=Xcomma\\,foobar.txt', @:)
+
+    call feedkeys(':set dictionary=Xcomma\\\,foo' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+    call assert_equal('"set dictionary=Xcomma\\,foobar.txt', @:)
+
+    " completion for :set dictionary= with escaped commas (same behavior, but
+    " different internal code path from 'set tags=' for escaping the output)
+    call feedkeys(':set dictionary=Xcomma\\,foo' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+    call assert_equal('"set dictionary=Xcomma\\,foobar.txt', @:)
+  endif
+  set tags&
+  set dictionary&
+
+  " completion for :set makeprg= with no escaped commas
+  call feedkeys(':set makeprg=Xcomma,foo' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"set makeprg=Xcomma,foobar.txt', @:)
+
+  if !has('win32')
+    " Cannot create file with backslash in file name in Windows, so only test
+    " this elsewhere.
+    defer delete('Xcomma\,fooslash.txt')
+    call writefile([], 'Xcomma\,fooslash.txt')
+    call feedkeys(':set makeprg=Xcomma\\,foo' .. "\<C-A>\<C-B>\"\<CR>", 'xt')
+    call assert_equal('"set makeprg=Xcomma\\,fooslash.txt', @:)
+  endif
+  set makeprg&
 
   " completion for the :py3 commands
   call feedkeys(":py3\<C-A>\<C-B>\"\<CR>", 'xt')
diff --git a/src/testdir/test_options.vim b/src/testdir/test_options.vim
index 2f6c8d2..ba08089 100644
--- a/src/testdir/test_options.vim
+++ b/src/testdir/test_options.vim
@@ -314,6 +314,7 @@
   call feedkeys(":set cdpath=./\<C-A>\<C-B>\"\<CR>", 'tx')
   call assert_match(' ./samples/ ', @:)
   call assert_notmatch(' ./summarize.vim ', @:)
+  set cdpath&
 
   " Expand files and directories.
   call feedkeys(":set tags=./\<C-A>\<C-B>\"\<CR>", 'tx')
@@ -321,7 +322,50 @@
 
   call feedkeys(":set tags=./\\\\ dif\<C-A>\<C-B>\"\<CR>", 'tx')
   call assert_equal('"set tags=./\\ diff diffexpr diffopt', @:)
-  set tags&
+
+  " Expand files with spaces/commas in them. Make sure we delimit correctly.
+  "
+  " 'tags' allow for for spaces/commas to both act as delimiters, with actual
+  " spaces requiring double escape, and commas need a single escape.
+  " 'dictionary' is a normal comma-separated option where only commas act as
+  " delimiters, and both space/comma need one single escape.
+  " 'makeprg' is a non-comma-separated option. Commas don't need escape.
+  defer delete('Xfoo Xspace.txt')
+  defer delete('Xsp_dummy')
+  defer delete('Xbar,Xcomma.txt')
+  defer delete('Xcom_dummy')
+  call writefile([], 'Xfoo Xspace.txt')
+  call writefile([], 'Xsp_dummy')
+  call writefile([], 'Xbar,Xcomma.txt')
+  call writefile([], 'Xcom_dummy')
+
+  call feedkeys(':set tags=./Xfoo\ Xsp' .. "\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"set tags=./Xfoo\ Xsp_dummy', @:)
+  call feedkeys(':set tags=./Xfoo\\\ Xsp' .. "\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"set tags=./Xfoo\\\ Xspace.txt', @:)
+  call feedkeys(':set dictionary=./Xfoo\ Xsp' .. "\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"set dictionary=./Xfoo\ Xspace.txt', @:)
+
+  call feedkeys(':set dictionary=./Xbar,Xcom' .. "\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"set dictionary=./Xbar,Xcom_dummy', @:)
+  if has('win32')
+    " In Windows, '\,' is literal, see `:help filename-backslash`, so this
+    " means we treat it as one file name.
+    call feedkeys(':set dictionary=Xbar\,Xcom' .. "\<C-A>\<C-B>\"\<CR>", 'tx')
+    call assert_equal('"set dictionary=Xbar\,Xcomma.txt', @:)
+  else
+    " In other platforms, '\,' simply escape to ',', and indicate a delimiter
+    " to split into a separate file name. You need '\\,' to escape the comma
+    " as part of the file name.
+    call feedkeys(':set dictionary=Xbar\,Xcom' .. "\<C-A>\<C-B>\"\<CR>", 'tx')
+    call assert_equal('"set dictionary=Xbar\,Xcom_dummy', @:)
+
+    call feedkeys(':set dictionary=Xbar\\,Xcom' .. "\<C-A>\<C-B>\"\<CR>", 'tx')
+    call assert_equal('"set dictionary=Xbar\\,Xcomma.txt', @:)
+  endif
+  call feedkeys(":set makeprg=./Xbar,Xcom\<C-A>\<C-B>\"\<CR>", 'tx')
+  call assert_equal('"set makeprg=./Xbar,Xcomma.txt', @:)
+  set tags& dictionary& makeprg&
 
   " Expanding the option names
   call feedkeys(":set \<Tab>\<C-B>\"\<CR>", 'xt')
diff --git a/src/version.c b/src/version.c
index 56f317d..458b46a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2009,
+/**/
     2008,
 /**/
     2007,