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From 5cc964e88bc34721a1e718004c450ce20a9fb428 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Sun, 3 Apr 2016 16:04:20 +0200
Subject: [PATCH 1/6] lib557: allow too long lines

Upstream-commit: adeaf95e2058a842badaddeae5501c0f5133dbea
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 tests/libtest/lib557.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/tests/libtest/lib557.c b/tests/libtest/lib557.c
index 2c0d5e0..2e72489 100644
--- a/tests/libtest/lib557.c
+++ b/tests/libtest/lib557.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -453,6 +453,7 @@ static int test_unsigned_int_formatting(void)
 
 #elif (SIZEOF_INT == 8)
 
+  /* !checksrc! disable LONGLINE all */
   i=1; ui_test[i].num = 0xFFFFFFFFFFFFFFFFU; ui_test[i].expected = "18446744073709551615";
   i++; ui_test[i].num = 0xFFFFFFFF00000000U; ui_test[i].expected = "18446744069414584320";
   i++; ui_test[i].num = 0x00000000FFFFFFFFU; ui_test[i].expected = "4294967295";
@@ -1344,6 +1345,7 @@ static int test_curl_off_t_formatting(void)
   num_cofft_tests = i;
 
 #endif
+  /* !checksrc! enable LONGLINE */
 
   for(i=1; i<=num_cofft_tests; i++) {
 
@@ -1351,11 +1353,12 @@ static int test_curl_off_t_formatting(void)
       co_test[i].result[j] = 'X';
     co_test[i].result[BUFSZ-1] = '\0';
 
-    (void)curl_msprintf(co_test[i].result, "%" CURL_FORMAT_CURL_OFF_T, co_test[i].num);
+    (void)curl_msprintf(co_test[i].result, "%" CURL_FORMAT_CURL_OFF_T,
+                        co_test[i].num);
 
     if(memcmp(co_test[i].result,
-               co_test[i].expected,
-               strlen(co_test[i].expected))) {
+              co_test[i].expected,
+              strlen(co_test[i].expected))) {
       printf("curl_off_t test #%.2d: Failed (Expected: %s Got: %s)\n",
              i, co_test[i].expected, co_test[i].result);
       failed++;
-- 
2.7.4


From 1e8206bd84b5bd2a41ea80631b6815d00c4ed813 Mon Sep 17 00:00:00 2001
From: Jay Satiro <raysatiro@yahoo.com>
Date: Wed, 9 Mar 2016 02:59:05 -0500
Subject: [PATCH 2/6] mprintf: Fix processing of width and prec args

Prior to this change a width arg could be erroneously output, and also
width and precision args could not be used together without crashing.

"%0*d%s", 2, 9, "foo"

Before: "092"
After: "09foo"

"%*.*s", 5, 2, "foo"

Before: crash
After: "   fo"

Test 557 is updated to verify this and more

Upstream-commit: 68701e51c1f794df59d9f70bcddbf714ee91b868
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 lib/mprintf.c          | 60 +++++++++++++++++++++++++++++++++-----------------
 tests/data/test557     |  1 +
 tests/libtest/lib557.c | 49 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 90 insertions(+), 20 deletions(-)

diff --git a/lib/mprintf.c b/lib/mprintf.c
index e47c10a..a110785 100644
--- a/lib/mprintf.c
+++ b/lib/mprintf.c
@@ -465,22 +465,24 @@ static long dprintf_Pass1(const char *format, va_stack_t *vto, char **endpos,
       if(flags & FLAGS_WIDTHPARAM) {
         /* we have the width specified from a parameter, so we make that
            parameter's info setup properly */
-        vto[i].width = width - 1;
-        i = width - 1;
-        vto[i].type = FORMAT_WIDTH;
-        vto[i].flags = FLAGS_NEW;
-        vto[i].precision = vto[i].width = 0; /* can't use width or precision
-                                                of width! */
+        long k = width - 1;
+        vto[i].width = k;
+        vto[k].type = FORMAT_WIDTH;
+        vto[k].flags = FLAGS_NEW;
+        /* can't use width or precision of width! */
+        vto[k].width = 0;
+        vto[k].precision = 0;
       }
       if(flags & FLAGS_PRECPARAM) {
         /* we have the precision specified from a parameter, so we make that
            parameter's info setup properly */
-        vto[i].precision = precision - 1;
-        i = precision - 1;
-        vto[i].type = FORMAT_WIDTH;
-        vto[i].flags = FLAGS_NEW;
-        vto[i].precision = vto[i].width = 0; /* can't use width or precision
-                                                of width! */
+        long k = precision - 1;
+        vto[i].precision = k;
+        vto[k].type = FORMAT_WIDTH;
+        vto[k].flags = FLAGS_NEW;
+        /* can't use width or precision of width! */
+        vto[k].width = 0;
+        vto[k].precision = 0;
       }
       *endpos++ = fmt + 1; /* end of this sequence */
     }
@@ -488,11 +490,15 @@ static long dprintf_Pass1(const char *format, va_stack_t *vto, char **endpos,
 
   /* Read the arg list parameters into our data list */
   for(i=0; i<max_param; i++) {
-    if((i + 1 < max_param) && (vto[i + 1].type == FORMAT_WIDTH)) {
-      /* Width/precision arguments must be read before the main argument
-       * they are attached to
-       */
-      vto[i + 1].data.num.as_signed = (mp_intmax_t)va_arg(arglist, int);
+    /* Width/precision arguments must be read before the main argument
+       they are attached to */
+    if(vto[i].flags & FLAGS_WIDTHPARAM) {
+      vto[vto[i].width].data.num.as_signed =
+        (mp_intmax_t)va_arg(arglist, int);
+    }
+    if(vto[i].flags & FLAGS_PRECPARAM) {
+      vto[vto[i].precision].data.num.as_signed =
+        (mp_intmax_t)va_arg(arglist, int);
     }
 
     switch (vto[i].type) {
@@ -645,16 +651,30 @@ static int dprintf_formatf(
     p = &vto[param];
 
     /* pick up the specified width */
-    if(p->flags & FLAGS_WIDTHPARAM)
+    if(p->flags & FLAGS_WIDTHPARAM) {
       width = (long)vto[p->width].data.num.as_signed;
+      param_num++; /* since the width is extracted from a parameter, we
+                      must skip that to get to the next one properly */
+      if(width < 0) {
+        /* "A negative field width is taken as a '-' flag followed by a
+           positive field width." */
+        width = -width;
+        p->flags |= FLAGS_LEFT;
+        p->flags &= ~FLAGS_PAD_NIL;
+      }
+    }
     else
       width = p->width;
 
     /* pick up the specified precision */
     if(p->flags & FLAGS_PRECPARAM) {
       prec = (long)vto[p->precision].data.num.as_signed;
-      param_num++; /* since the precision is extraced from a parameter, we
+      param_num++; /* since the precision is extracted from a parameter, we
                       must skip that to get to the next one properly */
+      if(prec < 0)
+        /* "A negative precision is taken as if the precision were
+           omitted." */
+        prec = -1;
     }
     else if(p->flags & FLAGS_PREC)
       prec = p->precision;
@@ -809,7 +829,7 @@ static int dprintf_formatf(
         else
           len = strlen(str);
 
-        width -= (long)len;
+        width -= (len > LONG_MAX) ? LONG_MAX : (long)len;
 
         if(p->flags & FLAGS_ALT)
           OUTCHAR('"');
diff --git a/tests/data/test557 b/tests/data/test557
index ee2793f..8d0944a 100644
--- a/tests/data/test557
+++ b/tests/data/test557
@@ -39,6 +39,7 @@ All curl_mprintf() signed int tests OK!
 All curl_mprintf() unsigned long tests OK!
 All curl_mprintf() signed long tests OK!
 All curl_mprintf() curl_off_t tests OK!
+All curl_mprintf() strings tests OK!
 </stdout>
 </verify>
 
diff --git a/tests/libtest/lib557.c b/tests/libtest/lib557.c
index 2e72489..5bdb8ab 100644
--- a/tests/libtest/lib557.c
+++ b/tests/libtest/lib557.c
@@ -1374,6 +1374,53 @@ static int test_curl_off_t_formatting(void)
   return failed;
 }
 
+static int string_check(char *buf, const char *buf2)
+{
+  if(strcmp(buf, buf2)) {
+    /* they shouldn't differ */
+    printf("sprintf failed:\nwe '%s'\nsystem: '%s'\n",
+           buf, buf2);
+    return 1;
+  }
+  return 0;
+}
+
+/*
+ * The output strings in this test need to have been verified with a system
+ * sprintf() before used here.
+ */
+static int test_string_formatting(void)
+{
+  int errors = 0;
+  char buf[256];
+  curl_msnprintf(buf, sizeof(buf), "%0*d%s", 2, 9, "foo");
+  errors += string_check(buf, "09foo");
+
+  curl_msnprintf(buf, sizeof(buf), "%*.*s", 5, 2, "foo");
+  errors += string_check(buf, "   fo");
+
+  curl_msnprintf(buf, sizeof(buf), "%*.*s", 2, 5, "foo");
+  errors += string_check(buf, "foo");
+
+  curl_msnprintf(buf, sizeof(buf), "%*.*s", 0, 10, "foo");
+  errors += string_check(buf, "foo");
+
+  curl_msnprintf(buf, sizeof(buf), "%-10s", "foo");
+  errors += string_check(buf, "foo       ");
+
+  curl_msnprintf(buf, sizeof(buf), "%10s", "foo");
+  errors += string_check(buf, "       foo");
+
+  curl_msnprintf(buf, sizeof(buf), "%*.*s", -10, -10, "foo");
+  errors += string_check(buf, "foo       ");
+
+  if(!errors)
+    printf("All curl_mprintf() strings tests OK!\n");
+  else
+    printf("Some curl_mprintf() string tests Failed!\n");
+
+  return errors;
+}
 
 int test(char *URL)
 {
@@ -1394,6 +1441,8 @@ int test(char *URL)
 
   errors += test_curl_off_t_formatting();
 
+  errors += test_string_formatting();
+
   if(errors)
     return TEST_ERR_MAJOR_BAD;
   else
-- 
2.7.4


From cf803e5d0041aaf77b95506a49895b7fa78c9541 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Sat, 8 Oct 2016 20:47:04 +0200
Subject: [PATCH 3/6] mprintf: return error on too many arguments

128 arguments should be enough for everyone

Upstream-commit: 71588c9aef8112025c7525d20f57eb367a947344
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 lib/mprintf.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/lib/mprintf.c b/lib/mprintf.c
index a110785..f51fe6d 100644
--- a/lib/mprintf.c
+++ b/lib/mprintf.c
@@ -232,10 +232,12 @@ static bool dprintf_IsQualifierNoDollar(const char *fmt)
  * Create an index with the type of each parameter entry and its
  * value (may vary in size)
  *
+ * Returns zero on success.
+ *
  ******************************************************************/
 
-static long dprintf_Pass1(const char *format, va_stack_t *vto, char **endpos,
-                          va_list arglist)
+static int dprintf_Pass1(const char *format, va_stack_t *vto, char **endpos,
+                         va_list arglist)
 {
   char *fmt = (char *)format;
   int param_num = 0;
@@ -398,6 +400,10 @@ static long dprintf_Pass1(const char *format, va_stack_t *vto, char **endpos,
 
       i = this_param - 1;
 
+      if((i < 0) || (i >= MAX_PARAMETERS))
+        /* out of allowed range */
+        return 1;
+
       switch (*fmt) {
       case 'S':
         flags |= FLAGS_ALT;
@@ -554,7 +560,7 @@ static long dprintf_Pass1(const char *format, va_stack_t *vto, char **endpos,
     }
   }
 
-  return max_param;
+  return 0;
 
 }
 
@@ -587,7 +593,8 @@ static int dprintf_formatf(
   va_stack_t *p;
 
   /* Do the actual %-code parsing */
-  dprintf_Pass1(format, vto, endpos, ap_save);
+  if(dprintf_Pass1(format, vto, endpos, ap_save))
+    return -1;
 
   end = &endpos[0]; /* the initial end-position from the list dprintf_Pass1()
                        created for us */
@@ -994,7 +1001,7 @@ int curl_mvsnprintf(char *buffer, size_t maxlength, const char *format,
   info.max = maxlength;
 
   retcode = dprintf_formatf(&info, addbyter, format, ap_save);
-  if(info.max) {
+  if((retcode != -1) && info.max) {
     /* we terminate this with a zero byte */
     if(info.max == info.length)
       /* we're at maximum, scrap the last letter */
-- 
2.7.4


From 329eb5d7f36049fa294dac1f89125ae5dd41fd84 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Sat, 8 Oct 2016 20:47:44 +0200
Subject: [PATCH 4/6] test557: verify printf() with 128 and 129 arguments

Upstream-commit: ac8a3149133fd3420770baf37190e47f5f7a46c7
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 tests/libtest/lib557.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)

diff --git a/tests/libtest/lib557.c b/tests/libtest/lib557.c
index 5bdb8ab..683ca08 100644
--- a/tests/libtest/lib557.c
+++ b/tests/libtest/lib557.c
@@ -1422,11 +1422,115 @@ static int test_string_formatting(void)
   return errors;
 }
 
+static int test_weird_arguments(void)
+{
+  int errors = 0;
+  char buf[256];
+  int rc;
+
+  /* MAX_PARAMETERS is 128, try exact 128! */
+  rc = curl_msnprintf(buf, sizeof(buf),
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 1 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 2 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 3 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 4 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 5 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 6 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 7 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 8 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 9 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 10 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 11 */
+                      "%d%d%d%d%d%d%d%d"     /* 8 */
+                      ,
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 1 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 2 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 3 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 4 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 5 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 6 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 7 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 8 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 9 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 10 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 11 */
+                      0, 1, 2, 3, 4, 5, 6, 7); /* 8 */
+
+  if(rc != 128) {
+    printf("curl_mprintf() returned %d and not 128!\n", rc);
+    errors++;
+  }
+
+  errors += string_check(buf,
+                         "0123456789" /* 10 */
+                         "0123456789" /* 10 1 */
+                         "0123456789" /* 10 2 */
+                         "0123456789" /* 10 3 */
+                         "0123456789" /* 10 4 */
+                         "0123456789" /* 10 5 */
+                         "0123456789" /* 10 6 */
+                         "0123456789" /* 10 7 */
+                         "0123456789" /* 10 8 */
+                         "0123456789" /* 10 9 */
+                         "0123456789" /* 10 10*/
+                         "0123456789" /* 10 11 */
+                         "01234567"   /* 8 */
+    );
+
+  /* MAX_PARAMETERS is 128, try more! */
+  buf[0] = 0;
+  rc = curl_msnprintf(buf, sizeof(buf),
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 1 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 2 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 3 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 4 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 5 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 6 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 7 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 8 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 9 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 10 */
+                      "%d%d%d%d%d%d%d%d%d%d" /* 10 11 */
+                      "%d%d%d%d%d%d%d%d%d"   /* 9 */
+                      ,
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 1 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 2 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 3 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 4 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 5 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 6 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 7 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 8 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 9 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 10 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, /* 10 11 */
+                      0, 1, 2, 3, 4, 5, 6, 7, 8);   /* 9 */
+
+  if(rc != -1) {
+    printf("curl_mprintf() returned %d and not -1!\n", rc);
+    errors++;
+  }
+
+  errors += string_check(buf, "");
+
+  if(errors)
+    printf("Some curl_mprintf() weird arguments tests failed!\n");
+
+  return errors;
+}
+
+
 int test(char *URL)
 {
   int errors = 0;
   (void)URL; /* not used */
 
+  errors += test_weird_arguments();
+
   errors += test_unsigned_short_formatting();
 
   errors += test_signed_short_formatting();
-- 
2.7.4


From 7ad1cdfb256f7e1b84fc960a8ca1403cca5d930f Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Tue, 8 Nov 2016 15:30:33 +0100
Subject: [PATCH 5/6] printf: fix ".*f" handling

It would always use precision 1 instead of reading it from the argument
list as intended.

Reported-by: Ray Satiro

Bug: #1113

Upstream-commit: 5dd1b65f79bc6dc75b752c53f3fa853b2a3b6d69
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 lib/mprintf.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/mprintf.c b/lib/mprintf.c
index f51fe6d..07830db 100644
--- a/lib/mprintf.c
+++ b/lib/mprintf.c
@@ -308,7 +308,6 @@ static int dprintf_Pass1(const char *format, va_stack_t *vto, char **endpos,
           flags |= FLAGS_ALT;
           break;
         case '.':
-          flags |= FLAGS_PREC;
           if('*' == *fmt) {
             /* The precision is picked from a specified parameter */
 
-- 
2.7.4


From 3162df571802b2c94d9969b6b269cd0d50c6650d Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Tue, 8 Nov 2016 15:32:37 +0100
Subject: [PATCH 6/6] printf: fix floating point buffer overflow issues

... and add a bunch of floating point printf tests

Upstream-commit: 3ab3c16db6a5674f53cf23d56512a405fde0b2c9
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 lib/mprintf.c          |  20 +++++++-
 tests/data/test557     |   1 +
 tests/libtest/lib557.c | 136 +++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 152 insertions(+), 5 deletions(-)

diff --git a/lib/mprintf.c b/lib/mprintf.c
index e1ad537..e3a690b 100644
--- a/lib/mprintf.c
+++ b/lib/mprintf.c
@@ -97,7 +97,8 @@
 #  define mp_uintmax_t unsigned long
 #endif
 
-#define BUFFSIZE 256 /* buffer for long-to-str and float-to-str calcs */
+#define BUFFSIZE 326 /* buffer for long-to-str and float-to-str calcs, should
+                        fit negative DBL_MAX (317 letters) */
 #define MAX_PARAMETERS 128 /* lame static limit */
 
 #ifdef __AMIGA__
@@ -918,12 +919,25 @@ static int dprintf_formatf(
         *fptr = 0;
 
         if(width >= 0) {
+          if(width >= (long)sizeof(work))
+            width = sizeof(work)-1;
           /* RECURSIVE USAGE */
           len = curl_msnprintf(fptr, left, "%ld", width);
           fptr += len;
           left -= len;
         }
         if(prec >= 0) {
+          /* for each digit in the integer part, we can have one less
+             precision */
+          size_t maxprec = sizeof(work) - 2;
+          double val = p->data.dnum;
+          while(val >= 10.0) {
+            val /= 10;
+            maxprec--;
+          }
+
+          if(prec > (long)maxprec)
+            prec = maxprec-1;
           /* RECURSIVE USAGE */
           len = curl_msnprintf(fptr, left, ".%ld", prec);
           fptr += len;
@@ -943,7 +957,9 @@ static int dprintf_formatf(
         /* NOTE NOTE NOTE!! Not all sprintf implementations return number of
            output characters */
         (sprintf)(work, formatbuf, p->data.dnum);
-
+#ifdef CURLDEBUG
+        assert(strlen(work) <= sizeof(work));
+#endif
         for(fptr=work; *fptr; fptr++)
           OUTCHAR(*fptr);
       }
diff --git a/tests/data/test557 b/tests/data/test557
index 8d0944a..ad9350f 100644
--- a/tests/data/test557
+++ b/tests/data/test557
@@ -40,6 +40,7 @@ All curl_mprintf() unsigned long tests OK!
 All curl_mprintf() signed long tests OK!
 All curl_mprintf() curl_off_t tests OK!
 All curl_mprintf() strings tests OK!
+All float strings tests OK!
 </stdout>
 </verify>
 
diff --git a/tests/libtest/lib557.c b/tests/libtest/lib557.c
index 683ca08..8c62a0e 100644
--- a/tests/libtest/lib557.c
+++ b/tests/libtest/lib557.c
@@ -1374,16 +1374,31 @@ static int test_curl_off_t_formatting(void)
   return failed;
 }
 
-static int string_check(char *buf, const char *buf2)
+static int _string_check(int linenumber, char *buf, const char *buf2)
 {
   if(strcmp(buf, buf2)) {
     /* they shouldn't differ */
-    printf("sprintf failed:\nwe '%s'\nsystem: '%s'\n",
-           buf, buf2);
+    printf("sprintf line %d failed:\nwe      '%s'\nsystem: '%s'\n",
+           linenumber, buf, buf2);
     return 1;
   }
   return 0;
 }
+#define string_check(x,y) _string_check(__LINE__, x, y)
+
+static int _strlen_check(int linenumber, char *buf, size_t len)
+{
+  size_t buflen = strlen(buf);
+  if(len != buflen) {
+    /* they shouldn't differ */
+    printf("sprintf strlen:%d failed:\nwe '%d'\nsystem: '%d'\n",
+           linenumber, buflen, len);
+    return 1;
+  }
+  return 0;
+}
+
+#define strlen_check(x,y) _strlen_check(__LINE__, x, y)
 
 /*
  * The output strings in this test need to have been verified with a system
@@ -1523,6 +1538,119 @@ static int test_weird_arguments(void)
   return errors;
 }
 
+/* DBL_MAX value from Linux */
+#define MAXIMIZE -179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368.000000
+
+static int test_float_formatting(void)
+{
+  int errors = 0;
+  char buf[512]; /* larger than max float size */
+  curl_msnprintf(buf, sizeof(buf), "%f", 9.0);
+  errors += string_check(buf, "9.000000");
+
+  curl_msnprintf(buf, sizeof(buf), "%.1f", 9.1);
+  errors += string_check(buf, "9.1");
+
+  curl_msnprintf(buf, sizeof(buf), "%.2f", 9.1);
+  errors += string_check(buf, "9.10");
+
+  curl_msnprintf(buf, sizeof(buf), "%.0f", 9.1);
+  errors += string_check(buf, "9");
+
+  curl_msnprintf(buf, sizeof(buf), "%0f", 9.1);
+  errors += string_check(buf, "9.100000");
+
+  curl_msnprintf(buf, sizeof(buf), "%10f", 9.1);
+  errors += string_check(buf, "  9.100000");
+
+  curl_msnprintf(buf, sizeof(buf), "%10.3f", 9.1);
+  errors += string_check(buf, "     9.100");
+
+  curl_msnprintf(buf, sizeof(buf), "%-10.3f", 9.1);
+  errors += string_check(buf, "9.100     ");
+
+  curl_msnprintf(buf, sizeof(buf), "%-10.3f", 9.123456);
+  errors += string_check(buf, "9.123     ");
+
+  curl_msnprintf(buf, sizeof(buf), "%.-2f", 9.1);
+  errors += string_check(buf, "9.100000");
+
+  curl_msnprintf(buf, sizeof(buf), "%*f", 10, 9.1);
+  errors += string_check(buf, "  9.100000");
+
+  curl_msnprintf(buf, sizeof(buf), "%*f", 3, 9.1);
+  errors += string_check(buf, "9.100000");
+
+  curl_msnprintf(buf, sizeof(buf), "%*f", 6, 9.2987654);
+  errors += string_check(buf, "9.298765");
+
+  curl_msnprintf(buf, sizeof(buf), "%*f", 6, 9.298765);
+  errors += string_check(buf, "9.298765");
+
+  curl_msnprintf(buf, sizeof(buf), "%*f", 6, 9.29876);
+  errors += string_check(buf, "9.298760");
+
+  curl_msnprintf(buf, sizeof(buf), "%.*f", 6, 9.2987654);
+  errors += string_check(buf, "9.298765");
+  curl_msnprintf(buf, sizeof(buf), "%.*f", 5, 9.2987654);
+  errors += string_check(buf, "9.29877");
+  curl_msnprintf(buf, sizeof(buf), "%.*f", 4, 9.2987654);
+  errors += string_check(buf, "9.2988");
+  curl_msnprintf(buf, sizeof(buf), "%.*f", 3, 9.2987654);
+  errors += string_check(buf, "9.299");
+  curl_msnprintf(buf, sizeof(buf), "%.*f", 2, 9.2987654);
+  errors += string_check(buf, "9.30");
+  curl_msnprintf(buf, sizeof(buf), "%.*f", 1, 9.2987654);
+  errors += string_check(buf, "9.3");
+  curl_msnprintf(buf, sizeof(buf), "%.*f", 0, 9.2987654);
+  errors += string_check(buf, "9");
+
+  /* very large precisions easily turn into system specific outputs so we only
+     check the output buffer length here as we know the internal limit */
+
+  curl_msnprintf(buf, sizeof(buf), "%.*f", (1<<30), 9.2987654);
+  errors += strlen_check(buf, 325);
+
+  curl_msnprintf(buf, sizeof(buf), "%10000.10000f", 9.2987654);
+  errors += strlen_check(buf, 325);
+
+  curl_msnprintf(buf, sizeof(buf), "%240.10000f",
+                 123456789123456789123456789.2987654);
+  errors += strlen_check(buf, 325);
+
+  /* 1<<31 turns negative (-2147483648) when used signed */
+  curl_msnprintf(buf, sizeof(buf), "%*f", (1<<31), 9.1);
+  errors += string_check(buf, "9.100000");
+
+  /* curl_msnprintf() limits a single float output to 325 bytes maximum
+     width */
+  curl_msnprintf(buf, sizeof(buf), "%*f", (1<<30), 9.1);
+  errors += string_check(buf, "                                                                                                                                                                                                                                                                                                                             9.100000");
+  curl_msnprintf(buf, sizeof(buf), "%100000f", 9.1);
+  errors += string_check(buf, "                                                                                                                                                                                                                                                                                                                             9.100000");
+
+  curl_msnprintf(buf, sizeof(buf), "%f", MAXIMIZE);
+  errors += strlen_check(buf, 317);
+
+  curl_msnprintf(buf, 2, "%f", MAXIMIZE);
+  errors += strlen_check(buf, 1);
+  curl_msnprintf(buf, 3, "%f", MAXIMIZE);
+  errors += strlen_check(buf, 2);
+  curl_msnprintf(buf, 4, "%f", MAXIMIZE);
+  errors += strlen_check(buf, 3);
+  curl_msnprintf(buf, 5, "%f", MAXIMIZE);
+  errors += strlen_check(buf, 4);
+  curl_msnprintf(buf, 6, "%f", MAXIMIZE);
+  errors += strlen_check(buf, 5);
+
+  if(!errors)
+    printf("All float strings tests OK!\n");
+  else
+    printf("test_float_formatting Failed!\n");
+
+  return errors;
+}
+
 
 int test(char *URL)
 {
@@ -1547,6 +1675,8 @@ int test(char *URL)
 
   errors += test_string_formatting();
 
+  errors += test_float_formatting();
+
   if(errors)
     return TEST_ERR_MAJOR_BAD;
   else
-- 
2.7.4