diff --git a/src/message.c b/src/message.c
index 037d456..12cb2c4 100644
--- a/src/message.c
+++ b/src/message.c
@@ -3991,6 +3991,28 @@
 #endif
 
 /*
+ * Return the representation of infinity for printf() function:
+ * "-inf", "inf", "+inf", " inf", "-INF", "INF", "+INF" or " INF".
+ */
+    static const char *
+infinity_str(int positive,
+	     char fmt_spec,
+	     int force_sign,
+	     int space_for_positive)
+{
+    static const char *table[] =
+    {
+	"-inf", "inf", "+inf", " inf",
+	"-INF", "INF", "+INF", " INF"
+    };
+    int idx = positive * (1 + force_sign + force_sign * space_for_positive);
+
+    if (ASCII_ISUPPER(fmt_spec))
+	idx += 4;
+    return table[idx];
+}
+
+/*
  * This code was included to provide a portable vsnprintf() and snprintf().
  * Some systems may provide their own, but we always use this one for
  * consistency.
@@ -4008,8 +4030,8 @@
  *
  * Limited support for floating point was added: 'f', 'e', 'E', 'g', 'G'.
  *
- * Length modifiers 'h' (short int) and 'l' (long int) are supported.
- * 'll' (long long int) is not supported.
+ * Length modifiers 'h' (short int) and 'l' (long int) and 'll' (long long int)
+ * are supported.
  *
  * The locale is not used, the string is used as a byte string.  This is only
  * relevant for double-byte encodings where the second byte may be '%'.
@@ -4397,7 +4419,7 @@
 		    uvarnumber_T ullong_arg = 0;
 # endif
 
-		    /* only defined for b convertion */
+		    /* only defined for b conversion */
 		    uvarnumber_T bin_arg = 0;
 
 		    /* pointer argument value -only defined for p
@@ -4702,7 +4724,6 @@
 		    char	format[40];
 		    int		l;
 		    int		remove_trailing_zeroes = FALSE;
-		    char	*s;
 
 		    f =
 #  if defined(FEAT_EVAL)
@@ -4732,16 +4753,10 @@
 			    )
 		    {
 			/* Avoid a buffer overflow */
-			if (f < 0)
-			{
-			    strcpy(tmp, "-inf");
-			    str_arg_l = 4;
-			}
-			else
-			{
-			    strcpy(tmp, "inf");
-			    str_arg_l = 3;
-			}
+			STRCPY(tmp, infinity_str(f > 0.0, fmt_spec,
+					      force_sign, space_for_positive));
+			str_arg_l = STRLEN(tmp);
+			zero_padding = 0;
 		    }
 		    else
 		    {
@@ -4761,23 +4776,25 @@
 			}
 			format[l] = fmt_spec;
 			format[l + 1] = NUL;
-			str_arg_l = sprintf(tmp, format, f);
 
-			/* Be consistent: Change "1.#IND" to "nan" and
-			 * "1.#INF" to "inf". */
-			s = *tmp == '-' ? tmp + 1 : tmp;
-			if (STRNCMP(s, "1.#INF", 6) == 0)
-			    STRCPY(s, "inf");
-			else if (STRNCMP(s, "1.#IND", 6) == 0)
-			    STRCPY(s, "nan");
-
-			/* Remove sign before "nan". */
-			if (STRNCMP(tmp, "-nan", 4) == 0)
-			    STRCPY(tmp, "nan");
-
-			/* Add sign before "inf" if needed. */
-			if (isinf(f) == -1 && STRNCMP(tmp, "inf", 3) == 0)
-			    STRCPY(tmp, "-inf");
+			if (isnan(f))
+			{
+			    /* Not a number: nan or NAN */
+			    STRCPY(tmp, ASCII_ISUPPER(fmt_spec) ? "NAN"
+								      : "nan");
+			    str_arg_l = 3;
+			    zero_padding = 0;
+			}
+			else if (isinf(f))
+			{
+			    STRCPY(tmp, infinity_str(f > 0.0, fmt_spec,
+					      force_sign, space_for_positive));
+			    str_arg_l = STRLEN(tmp);
+			    zero_padding = 0;
+			}
+			else
+			    /* Regular float number */
+			    str_arg_l = sprintf(tmp, format, f);
 
 			if (remove_trailing_zeroes)
 			{
diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
index 6f1de59..11ca288 100644
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -154,13 +154,22 @@
   call assert_equal(' 123', printf('%  d', 123))
   call assert_equal('-123', printf('% d', -123))
 
+  call assert_equal('123', printf('%2d', 123))
+  call assert_equal('   123', printf('%6d', 123))
+  call assert_equal('000123', printf('%06d', 123))
+  call assert_equal('+00123', printf('%+06d', 123))
+  call assert_equal(' 00123', printf('% 06d', 123))
+  call assert_equal('  +123', printf('%+6d', 123))
+  call assert_equal('   123', printf('% 6d', 123))
+  call assert_equal('  -123', printf('% 6d', -123))
+  call assert_equal('+123  ', printf('%-+6d', 123))
+  call assert_equal(' 123  ', printf('%- 6d', 123))
+  call assert_equal('-123  ', printf('%- 6d', -123))
+
   call assert_equal('00123', printf('%.*d', 5, 123))
   call assert_equal('  123', printf('% *d', 5, 123))
   call assert_equal(' +123', printf('%+ *d', 5, 123))
 
-  call assert_equal('123', printf('%2d', 123))
-  call assert_equal('  123', printf('%5d', 123))
-  call assert_equal('00123', printf('%05d', 123))
   call assert_equal('123  ', printf('%-5d', 123))
   call assert_equal('0x7b', printf('%#x', 123))
   call assert_equal('0X7B', printf('%#X', 123))
@@ -194,20 +203,81 @@
   if has('float')
     call assert_equal('1.230000', printf('%f', 1.23))
     call assert_equal('1.230000', printf('%F', 1.23))
-    call assert_equal('1.23', printf('%g', 1.23))
-    call assert_equal('1.23', printf('%G', 1.23))
+    call assert_equal('9999999.9', printf('%g', 9999999.9))
+    call assert_equal('9999999.9', printf('%G', 9999999.9))
+    call assert_equal('1.00000001e7', printf('%.8g', 10000000.1))
+    call assert_equal('1.00000001E7', printf('%.8G', 10000000.1))
     call assert_equal('1.230000e+00', printf('%e', 1.23))
     call assert_equal('1.230000E+00', printf('%E', 1.23))
     call assert_equal('1.200000e-02', printf('%e', 0.012))
     call assert_equal('-1.200000e-02', printf('%e', -0.012))
-    call assert_equal('1.2', printf('%.1f', 1.23))
+    call assert_equal('0.33', printf('%.2f', 1.0/3.0))
+    call assert_equal('  0.33', printf('%6.2f', 1.0/3.0))
+    call assert_equal(' -0.33', printf('%6.2f', -1.0/3.0))
+    call assert_equal('000.33', printf('%06.2f', 1.0/3.0))
+    " FIXME: call assert_equal('-00.33', printf('%06.2f', -1.0/3.0))
+    " FIXME: call assert_equal('-00.33', printf('%+06.2f', -1.0/3.0))
+    " FIXME: call assert_equal('+00.33', printf('%+06.2f', 1.0/3.0))
+    " FIXME: call assert_equal(' 00.33', printf('% 06.2f', 1.0/3.0))
 
+    " Float infinity can be signed.
     call assert_equal('inf', printf('%f', 1.0/0.0))
+    call assert_equal('-inf', printf('%f', -1.0/0.0))
+    call assert_equal('inf', printf('%g', 1.0/0.0))
+    call assert_equal('-inf', printf('%g', -1.0/0.0))
+    call assert_equal('inf', printf('%e', 1.0/0.0))
+    call assert_equal('-inf', printf('%e', -1.0/0.0))
+    call assert_equal('INF', printf('%E', 1.0/0.0))
+    call assert_equal('-INF', printf('%E', -1.0/0.0))
+    call assert_equal('INF', printf('%E', 1.0/0.0))
+    call assert_equal('-INF', printf('%G', -1.0/0.0))
+    call assert_equal('+inf', printf('%+f', 1.0/0.0))
+    call assert_equal('-inf', printf('%+f', -1.0/0.0))
+    call assert_equal(' inf', printf('% f',  1.0/0.0))
+    call assert_equal('   inf', printf('%6f', 1.0/0.0))
+    call assert_equal('  -inf', printf('%6f', -1.0/0.0))
+    call assert_equal('   inf', printf('%6g', 1.0/0.0))
+    call assert_equal('  -inf', printf('%6g', -1.0/0.0))
+    call assert_equal('  +inf', printf('%+6f', 1.0/0.0))
+    call assert_equal('   inf', printf('% 6f', 1.0/0.0))
+    call assert_equal('  +inf', printf('%+06f', 1.0/0.0))
+    call assert_equal('inf   ', printf('%-6f', 1.0/0.0))
+    call assert_equal('-inf  ', printf('%-6f', -1.0/0.0))
+    call assert_equal('+inf  ', printf('%-+6f', 1.0/0.0))
+    call assert_equal(' inf  ', printf('%- 6f', 1.0/0.0))
+    call assert_equal('INF   ', printf('%-6G', 1.0/0.0))
+    call assert_equal('-INF  ', printf('%-6G', -1.0/0.0))
+    call assert_equal('INF   ', printf('%-6E', 1.0/0.0))
+    call assert_equal('-INF  ', printf('%-6E', -1.0/0.0))
+    call assert_equal('inf', printf('%s', 1.0/0.0))
+    call assert_equal('-inf', printf('%s', -1.0/0.0))
 
-    call assert_match('^-inf$', printf('%f', -1.0/0.0))
+    " Float zero can be signed.
+    call assert_equal('0.000000', printf('%f', 1.0/(1.0/0.0)))
+    call assert_equal('-0.000000', printf('%f', 1.0/(-1.0/0.0)))
+    call assert_equal('0.0', printf('%s', 1.0/(1.0/0.0)))
+    call assert_equal('-0.0', printf('%s', 1.0/(-1.0/0.0)))
+    call assert_equal('0.0', printf('%S', 1.0/(1.0/0.0)))
+    call assert_equal('-0.0', printf('%S', 1.0/(-1.0/0.0)))
 
-    call assert_match('^nan$', printf('%f', sqrt(-1.0)))
-    call assert_match('^nan$', printf('%f', 0.0/0.0))
+    " Float nan (not a number) has no sign.
+    call assert_equal('nan', printf('%f', sqrt(-1.0)))
+    call assert_equal('nan', printf('%f', 0.0/0.0))
+    call assert_equal('nan', printf('%f', -0.0/0.0))
+    call assert_equal('nan', printf('%g', 0.0/0.0))
+    call assert_equal('nan', printf('%e', 0.0/0.0))
+    call assert_equal('NAN', printf('%G', 0.0/0.0))
+    call assert_equal('NAN', printf('%E', 0.0/0.0))
+    call assert_equal('NAN', printf('%G', -0.0/0.0))
+    call assert_equal('NAN', printf('%E', -0.0/0.0))
+    call assert_equal('   nan', printf('%6f', 0.0/0.0))
+    call assert_equal('   nan', printf('%06f', 0.0/0.0))
+    call assert_equal('nan   ', printf('%-6f', 0.0/0.0))
+    call assert_equal('nan   ', printf('%- 6f', 0.0/0.0))
+    call assert_equal('nan', printf('%s', 0.0/0.0))
+    call assert_equal('nan', printf('%s', -0.0/0.0))
+    call assert_equal('nan', printf('%S', 0.0/0.0))
+    call assert_equal('nan', printf('%S', -0.0/0.0))
 
     call assert_fails('echo printf("%f", "a")', 'E807:')
   endif
diff --git a/src/version.c b/src/version.c
index 007a56c..8bca417 100644
--- a/src/version.c
+++ b/src/version.c
@@ -764,6 +764,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2280,
+/**/
     2279,
 /**/
     2278,