diff --git a/src/diff.c b/src/diff.c
index 0bf0ef2..149022a 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -24,13 +24,17 @@
 static int	diff_busy = FALSE;	/* ex_diffgetput() is busy */
 
 /* flags obtained from the 'diffopt' option */
-#define DIFF_FILLER	1	// display filler lines
-#define DIFF_ICASE	2	// ignore case
-#define DIFF_IWHITE	4	// ignore change in white space
-#define DIFF_HORIZONTAL	8	// horizontal splits
-#define DIFF_VERTICAL	16	// vertical splits
-#define DIFF_HIDDEN_OFF	32	// diffoff when hidden
-#define DIFF_INTERNAL	64	// use internal xdiff algorithm
+#define DIFF_FILLER	0x001	// display filler lines
+#define DIFF_IBLANK	0x002	// ignore empty lines
+#define DIFF_ICASE	0x004	// ignore case
+#define DIFF_IWHITE	0x008	// ignore change in white space
+#define DIFF_IWHITEALL	0x010	// ignore all white space changes
+#define DIFF_IWHITEEOL	0x020	// ignore change in white space at EOL
+#define DIFF_HORIZONTAL	0x040	// horizontal splits
+#define DIFF_VERTICAL	0x080	// vertical splits
+#define DIFF_HIDDEN_OFF	0x100	// diffoff when hidden
+#define DIFF_INTERNAL	0x200	// use internal xdiff algorithm
+#define ALL_WHITE_DIFF (DIFF_IWHITE | DIFF_IWHITEALL | DIFF_IWHITEEOL)
 static int	diff_flags = DIFF_INTERNAL | DIFF_FILLER;
 
 static long diff_algorithm = 0;
@@ -1050,6 +1054,12 @@
 
     if (diff_flags & DIFF_IWHITE)
 	param.flags |= XDF_IGNORE_WHITESPACE_CHANGE;
+    if (diff_flags & DIFF_IWHITEALL)
+	param.flags |= XDF_IGNORE_WHITESPACE;
+    if (diff_flags & DIFF_IWHITEEOL)
+	param.flags |= XDF_IGNORE_WHITESPACE_AT_EOL;
+    if (diff_flags & DIFF_IBLANK)
+	param.flags |= XDF_IGNORE_BLANK_LINES;
 
     emit_cfg.ctxlen = 0; // don't need any diff_context here
     emit_cb.priv = &diffio->dio_diff;
@@ -1106,7 +1116,7 @@
 	// Build the diff command and execute it.  Always use -a, binary
 	// differences are of no use.  Ignore errors, diff returns
 	// non-zero when differences have been found.
-	vim_snprintf((char *)cmd, len, "diff %s%s%s%s%s %s",
+	vim_snprintf((char *)cmd, len, "diff %s%s%s%s%s%s%s%s %s",
 		diff_a_works == FALSE ? "" : "-a ",
 #if defined(MSWIN)
 		diff_bin_works == TRUE ? "--binary " : "",
@@ -1114,6 +1124,9 @@
 		"",
 #endif
 		(diff_flags & DIFF_IWHITE) ? "-b " : "",
+		(diff_flags & DIFF_IWHITEALL) ? "-w " : "",
+		(diff_flags & DIFF_IWHITEEOL) ? "-Z " : "",
+		(diff_flags & DIFF_IBLANK) ? "-B " : "",
 		(diff_flags & DIFF_ICASE) ? "-i " : "",
 		tmp_orig, tmp_new);
 	append_redir(cmd, (int)len, p_srr, tmp_diff);
@@ -1946,17 +1959,25 @@
     char_u	*p1, *p2;
     int		l;
 
-    if ((diff_flags & (DIFF_ICASE | DIFF_IWHITE)) == 0)
+    if ((diff_flags & DIFF_IBLANK)
+	    && (*skipwhite(s1) == NUL || *skipwhite(s2) == NUL))
+	return 0;
+
+    if ((diff_flags & (DIFF_ICASE | ALL_WHITE_DIFF)) == 0)
 	return STRCMP(s1, s2);
-    if ((diff_flags & DIFF_ICASE) && !(diff_flags & DIFF_IWHITE))
+    if ((diff_flags & DIFF_ICASE) && !(diff_flags & ALL_WHITE_DIFF))
 	return MB_STRICMP(s1, s2);
 
-    /* Ignore white space changes and possibly ignore case. */
     p1 = s1;
     p2 = s2;
+
+    // Ignore white space changes and possibly ignore case.
     while (*p1 != NUL && *p2 != NUL)
     {
-	if (VIM_ISWHITE(*p1) && VIM_ISWHITE(*p2))
+	if (((diff_flags & DIFF_IWHITE)
+		    && VIM_ISWHITE(*p1) && VIM_ISWHITE(*p2))
+		|| ((diff_flags & DIFF_IWHITEALL)
+		    && (VIM_ISWHITE(*p1) || VIM_ISWHITE(*p2))))
 	{
 	    p1 = skipwhite(p1);
 	    p2 = skipwhite(p2);
@@ -1970,7 +1991,7 @@
 	}
     }
 
-    /* Ignore trailing white space. */
+    // Ignore trailing white space.
     p1 = skipwhite(p1);
     p2 = skipwhite(p2);
     if (*p1 != NUL || *p2 != NUL)
@@ -2142,11 +2163,26 @@
 	    p += 8;
 	    diff_context_new = getdigits(&p);
 	}
+	else if (STRNCMP(p, "iblank", 6) == 0)
+	{
+	    p += 6;
+	    diff_flags_new |= DIFF_IBLANK;
+	}
 	else if (STRNCMP(p, "icase", 5) == 0)
 	{
 	    p += 5;
 	    diff_flags_new |= DIFF_ICASE;
 	}
+	else if (STRNCMP(p, "iwhiteall", 9) == 0)
+	{
+	    p += 9;
+	    diff_flags_new |= DIFF_IWHITEALL;
+	}
+	else if (STRNCMP(p, "iwhiteeol", 9) == 0)
+	{
+	    p += 9;
+	    diff_flags_new |= DIFF_IWHITEEOL;
+	}
 	else if (STRNCMP(p, "iwhite", 6) == 0)
 	{
 	    p += 6;
@@ -2315,9 +2351,12 @@
 	    si_org = si_new = 0;
 	    while (line_org[si_org] != NUL)
 	    {
-		if ((diff_flags & DIFF_IWHITE)
-			&& VIM_ISWHITE(line_org[si_org])
-			&& VIM_ISWHITE(line_new[si_new]))
+		if (((diff_flags & DIFF_IWHITE)
+			    && VIM_ISWHITE(line_org[si_org])
+					      && VIM_ISWHITE(line_new[si_new]))
+			|| ((diff_flags & DIFF_IWHITEALL)
+			    && (VIM_ISWHITE(line_org[si_org])
+					    || VIM_ISWHITE(line_new[si_new]))))
 		{
 		    si_org = (int)(skipwhite(line_org + si_org) - line_org);
 		    si_new = (int)(skipwhite(line_new + si_new) - line_new);
@@ -2351,9 +2390,12 @@
 		while (ei_org >= *startp && ei_new >= si_new
 						&& ei_org >= 0 && ei_new >= 0)
 		{
-		    if ((diff_flags & DIFF_IWHITE)
-			    && VIM_ISWHITE(line_org[ei_org])
-			    && VIM_ISWHITE(line_new[ei_new]))
+		    if (((diff_flags & DIFF_IWHITE)
+				&& VIM_ISWHITE(line_org[ei_org])
+					      && VIM_ISWHITE(line_new[ei_new]))
+			    || ((diff_flags & DIFF_IWHITEALL)
+				&& (VIM_ISWHITE(line_org[ei_org])
+					    || VIM_ISWHITE(line_new[ei_new]))))
 		    {
 			while (ei_org >= *startp
 					     && VIM_ISWHITE(line_org[ei_org]))
diff --git a/src/testdir/dumps/Test_diff_17.dump b/src/testdir/dumps/Test_diff_17.dump
new file mode 100644
index 0000000..101df35
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_17.dump
@@ -0,0 +1,20 @@
+| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1| +0#0000000#5fd7ff255@34||+1&#ffffff0| +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34
+| +0#0000e05#a8a8a8255@1|c+0#0000000#ffffff0|d| @32||+1&&| +0#0000e05#a8a8a8255@1|c+0#0000000#ffffff0|d| @32
+| +0#0000e05#a8a8a8255@1|e+0#0000000#ffffff0|f| @32||+1&&| +0#0000e05#a8a8a8255@1| +0#0000000#ffffff0@34
+| +0#0000e05#a8a8a8255@1|x+2#0000000#ff404010@2| +0&#ffd7ff255@31||+1&#ffffff0| +0#0000e05#a8a8a8255@1|e+0#0000000#ffffff0|f| @32
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|y+2#0000000#ff404010@2| +0&#ffd7ff255@31
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+|X+3#0000000&|f|i|l|e|1| @12|1|,|1| @11|A|l@1| |X+1&&|f|i|l|e|2| @12|1|,|1| @11|A|l@1
+|:+0&&> @73
diff --git a/src/testdir/dumps/Test_diff_18.dump b/src/testdir/dumps/Test_diff_18.dump
new file mode 100644
index 0000000..7f17531
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_18.dump
@@ -0,0 +1,20 @@
+| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1| +0#0000000#ffffff0@34||+1&&| +0#0000e05#a8a8a8255@1|c+0#0000000#ffffff0|d| @32
+| +0#0000e05#a8a8a8255@1|c+0#0000000#ffffff0|d| @32||+1&&| +0#0000e05#a8a8a8255@1| +0#0000000#ffffff0@34
+| +0#0000e05#a8a8a8255@1|e+0#0000000#ffffff0|f| @32||+1&&| +0#0000e05#a8a8a8255@1|e+0#0000000#ffffff0|f| @32
+| +0#0000e05#a8a8a8255@1|x+2#0000000#ff404010@2| +0&#ffd7ff255@31||+1&#ffffff0| +0#0000e05#a8a8a8255@1|y+2#0000000#ff404010@2| +0&#ffd7ff255@31
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+|X+3#0000000&|f|i|l|e|1| @12|1|,|1| @11|A|l@1| |X+1&&|f|i|l|e|2| @12|1|,|1| @11|A|l@1
+|:+0&&> @73
diff --git a/src/testdir/dumps/Test_diff_19.dump b/src/testdir/dumps/Test_diff_19.dump
new file mode 100644
index 0000000..f2d0611
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_19.dump
@@ -0,0 +1,20 @@
+| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|x+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|x+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|c+0#0000000#ffd7ff255|d| @32||+1&#ffffff0| +0#0000e05#a8a8a8255@1|c+0#0000000#ffd7ff255| +2&#ff404010|d+0&#ffd7ff255| @31
+| +0#0000e05#a8a8a8255@1|e+0#0000000#ffd7ff255|f| @32||+1&#ffffff0| +0#0000e05#a8a8a8255@1| +2#0000000#ff404010|e+0&#ffd7ff255|f| @31
+| +0#0000e05#a8a8a8255@1|x+0#0000000#ffd7ff255@1| | +2&#ff404010|x+0&#ffd7ff255@1| @28||+1&#ffffff0| +0#0000e05#a8a8a8255@1|x+0#0000000#ffd7ff255@1| |x@1| @29
+| +0#0000e05#a8a8a8255@1|f+0#0000000#ffffff0|o@1| @31||+1&&| +0#0000e05#a8a8a8255@1|f+0#0000000#ffffff0|o@1| @31
+| +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34||+1#0000000#ffffff0| +0#0000e05#a8a8a8255@1| +0#0000000#5fd7ff255@34
+| +0#0000e05#a8a8a8255@1|b+0#0000000#ffffff0|a|r| @31||+1&&| +0#0000e05#a8a8a8255@1|b+0#0000000#ffffff0|a|r| @31
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+|X+3#0000000&|f|i|l|e|1| @12|1|,|1| @11|A|l@1| |X+1&&|f|i|l|e|2| @12|1|,|1| @11|A|l@1
+|:+0&&> @73
diff --git a/src/testdir/dumps/Test_diff_20.dump b/src/testdir/dumps/Test_diff_20.dump
new file mode 100644
index 0000000..1dbd07c
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_20.dump
@@ -0,0 +1,20 @@
+| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|a+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|x+0#0000000#ffffff0| @33||+1&&| +0#0000e05#a8a8a8255@1|x+0#0000000#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|c+0#0000000#ffffff0|d| @32||+1&&| +0#0000e05#a8a8a8255@1|c+0#0000000#ffffff0| |d| @31
+| +0#0000e05#a8a8a8255@1|e+0#0000000#ffffff0|f| @32||+1&&| +0#0000e05#a8a8a8255@1| +0#0000000#ffffff0|e|f| @31
+| +0#0000e05#a8a8a8255@1|x+0#0000000#ffffff0@1| @1|x@1| @28||+1&&| +0#0000e05#a8a8a8255@1|x+0#0000000#ffffff0@1| |x@1| @29
+| +0#0000e05#a8a8a8255@1|f+0#0000000#ffffff0|o@1| @31||+1&&| +0#0000e05#a8a8a8255@1|f+0#0000000#ffffff0|o@1| @31
+| +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34||+1#0000000#ffffff0| +0#0000e05#a8a8a8255@1| +0#0000000#5fd7ff255@34
+| +0#0000e05#a8a8a8255@1|b+0#0000000#ffffff0|a|r| @31||+1&&| +0#0000e05#a8a8a8255@1|b+0#0000000#ffffff0|a|r| @31
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33||+1#0000000&| +0#0000e05#a8a8a8255@1|~+0#4040ff13#ffffff0| @33
+|X+3#0000000&|f|i|l|e|1| @12|1|,|1| @11|A|l@1| |X+1&&|f|i|l|e|2| @12|1|,|1| @11|A|l@1
+|:+0&&> @73
diff --git a/src/testdir/test_diffmode.vim b/src/testdir/test_diffmode.vim
index 0022a73..5ee22e2 100644
--- a/src/testdir/test_diffmode.vim
+++ b/src/testdir/test_diffmode.vim
@@ -671,16 +671,18 @@
   bwipe!
 endfunc
 
-func WriteDiffFiles(list1, list2)
+func WriteDiffFiles(buf, list1, list2)
   call writefile(a:list1, 'Xfile1')
   call writefile(a:list2, 'Xfile2')
+  if a:buf
+    call term_sendkeys(a:buf, ":checktime\<CR>")
+  endif
 endfunc
 
-" Verify a screendump with both the external and external diff.
+" Verify a screendump with both the internal and external diff.
 func VerifyBoth(buf, dumpfile, extra)
-  call term_sendkeys(a:buf, ":diffupdate!\<cr>")
   " trailing : for leaving the cursor on the command line
-  for cmd in [":set diffopt=filler" . a:extra . "\<cr>:", ":set diffopt+=internal\<cr>:"]
+  for cmd in [":set diffopt=filler" . a:extra . "\<CR>:", ":set diffopt+=internal\<CR>:"]
     call term_sendkeys(a:buf, cmd)
     if VerifyScreenDump(a:buf, a:dumpfile, {}, cmd =~ 'internal' ? 'internal' : 'external')
       break " don't let the next iteration overwrite the "failed" file.
@@ -688,6 +690,14 @@
   endfor
 endfunc
 
+" Verify a screendump with the internal diff only.
+func VerifyInternal(buf, dumpfile, extra)
+  call term_sendkeys(a:buf, ":diffupdate!\<CR>")
+  " trailing : for leaving the cursor on the command line
+  call term_sendkeys(a:buf, ":set diffopt=internal,filler" . a:extra . "\<CR>:")
+  call VerifyScreenDump(a:buf, a:dumpfile, {})
+endfunc
+
 func Test_diff_screen()
   if !CanRunVimInTerminal() || !has('menu')
     return
@@ -697,36 +707,36 @@
   call delete('.Xfile2.swp')
 
   " Test 1: Add a line in beginning of file 2
-  call WriteDiffFiles([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
+  call WriteDiffFiles(0, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10], [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
   let buf = RunVimInTerminal('-d Xfile1 Xfile2', {})
   " Set autoread mode, ,so that Vim won't complain once we re-write the test
   " files
-  call term_sendkeys(buf, ":set autoread\<cr>\<c-w>w:set autoread\<cr>\<c-w>w")
+  call term_sendkeys(buf, ":set autoread\<CR>\<c-w>w:set autoread\<CR>\<c-w>w")
 
   call VerifyBoth(buf, 'Test_diff_01', '')
 
   " Test 2: Add a line in beginning of file 1
-  call WriteDiffFiles([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
+  call WriteDiffFiles(buf, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
   call VerifyBoth(buf, 'Test_diff_02', '')
 
   " Test 3: Add a line at the end of file 2
-  call WriteDiffFiles([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])
+  call WriteDiffFiles(buf, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])
   call VerifyBoth(buf, 'Test_diff_03', '')
 
   " Test 4: Add a line at the end of file 1
-  call WriteDiffFiles([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
+  call WriteDiffFiles(buf, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
   call VerifyBoth(buf, 'Test_diff_04', '')
 
   " Test 5: Add a line in the middle of file 2, remove on at the end of file 1
-  call WriteDiffFiles([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11], [1, 2, 3, 4, 4, 5, 6, 7, 8, 9, 10])
+  call WriteDiffFiles(buf, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11], [1, 2, 3, 4, 4, 5, 6, 7, 8, 9, 10])
   call VerifyBoth(buf, 'Test_diff_05', '')
 
   " Test 6: Add a line in the middle of file 1, remove on at the end of file 2
-  call WriteDiffFiles([1, 2, 3, 4, 4, 5, 6, 7, 8, 9, 10], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])
+  call WriteDiffFiles(buf, [1, 2, 3, 4, 4, 5, 6, 7, 8, 9, 10], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])
   call VerifyBoth(buf, 'Test_diff_06', '')
 
   " Test 7 - 9: Test normal/patience/histogram diff algorithm
-  call WriteDiffFiles(['#include <stdio.h>', '', '// Frobs foo heartily', 'int frobnitz(int foo)', '{',
+  call WriteDiffFiles(buf, ['#include <stdio.h>', '', '// Frobs foo heartily', 'int frobnitz(int foo)', '{',
       \ '    int i;', '    for(i = 0; i < 10; i++)', '    {', '        printf("Your answer is: ");',
       \ '        printf("%d\n", foo);', '    }', '}', '', 'int fact(int n)', '{', '    if(n > 1)', '    {',
       \ '        return fact(n-1) * n;', '    }', '    return 1;', '}', '', 'int main(int argc, char **argv)',
@@ -748,7 +758,7 @@
 
   " Test 10-11: normal/indent-heuristic
   call term_sendkeys(buf, ":set diffopt&vim\<cr>")
-  call WriteDiffFiles(['', '  def finalize(values)', '', '    values.each do |v|', '      v.finalize', '    end'],
+  call WriteDiffFiles(buf, ['', '  def finalize(values)', '', '    values.each do |v|', '      v.finalize', '    end'],
       \ ['', '  def finalize(values)', '', '    values.each do |v|', '      v.prepare', '    end', '',
       \ '    values.each do |v|', '      v.finalize', '    end'])
   call term_sendkeys(buf, ":diffupdate!\<cr>")
@@ -759,19 +769,19 @@
   call VerifyScreenDump(buf, 'Test_diff_11', {})
 
   " Test 12: diff the same file
-  call WriteDiffFiles([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
+  call WriteDiffFiles(buf, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10], [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
   call VerifyBoth(buf, 'Test_diff_12', '')
 
   " Test 13: diff an empty file
-  call WriteDiffFiles([], [])
+  call WriteDiffFiles(buf, [], [])
   call VerifyBoth(buf, 'Test_diff_13', '')
 
   " Test 14: test diffopt+=icase
-  call WriteDiffFiles(['a', 'b', 'cd'], ['A', 'b', 'cDe'])
+  call WriteDiffFiles(buf, ['a', 'b', 'cd'], ['A', 'b', 'cDe'])
   call VerifyBoth(buf, 'Test_diff_14', " diffopt+=filler diffopt+=icase")
 
   " Test 15-16: test diffopt+=iwhite
-  call WriteDiffFiles(['int main()', '{', '   printf("Hello, World!");', '   return 0;', '}'],
+  call WriteDiffFiles(buf, ['int main()', '{', '   printf("Hello, World!");', '   return 0;', '}'],
       \ ['int main()', '{', '   if (0)', '   {', '      printf("Hello, World!");', '      return 0;', '   }', '}'])
   call term_sendkeys(buf, ":diffupdate!\<cr>")
   call term_sendkeys(buf, ":set diffopt&vim diffopt+=filler diffopt+=iwhite\<cr>")
@@ -779,6 +789,22 @@
   call term_sendkeys(buf, ":set diffopt+=internal\<cr>")
   call VerifyScreenDump(buf, 'Test_diff_16', {})
 
+  " Test 17: test diffopt+=iblank
+  call WriteDiffFiles(buf, ['a', ' ', 'cd', 'ef', 'xxx'], ['a', 'cd', '', 'ef', 'yyy'])
+  call VerifyInternal(buf, 'Test_diff_17', " diffopt+=iblank")
+
+  " Test 18: test diffopt+=iblank,iwhite / iwhiteall / iwhiteeol
+  call VerifyInternal(buf, 'Test_diff_18', " diffopt+=iblank,iwhite")
+  call VerifyInternal(buf, 'Test_diff_18', " diffopt+=iblank,iwhiteall")
+  call VerifyInternal(buf, 'Test_diff_18', " diffopt+=iblank,iwhiteeol")
+
+  " Test 19: test diffopt+=iwhiteeol
+  call WriteDiffFiles(buf, ['a ', 'x', 'cd', 'ef', 'xx  xx', 'foo', 'bar'], ['a', 'x', 'c d', ' ef', 'xx xx', 'foo', '', 'bar'])
+  call VerifyInternal(buf, 'Test_diff_19', " diffopt+=iwhiteeol")
+
+  " Test 19: test diffopt+=iwhiteall
+  call VerifyInternal(buf, 'Test_diff_20', " diffopt+=iwhiteall")
+
   " clean up
   call StopVimInTerminal(buf)
   call delete('Xfile1')
diff --git a/src/version.c b/src/version.c
index d04bdab..13b8aed 100644
--- a/src/version.c
+++ b/src/version.c
@@ -795,6 +795,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    393,
+/**/
     392,
 /**/
     391,