fix(printf): fixed floating point sign handling

2 files changed, 22 insertions, 4 deletions

diff --git a/printf.c b/printf.c
index 69c7ea7..418386a 100644
--- a/printf.c
+++ b/printf.c
@@ -303,16 +303,16 @@ static size_t _ftoa(double value, char* buffer, size_t maxlen, unsigned int prec
       break;

     }

   }

-  

+

   // pad leading zeros

-  while (!(flags & FLAGS_LEFT) && (len < prec) && (len < PRINTF_FTOA_BUFFER_SIZE)) {

-    buf[len++] = '0';

-  }

   while (!(flags & FLAGS_LEFT) && (flags & FLAGS_ZEROPAD) && (len < width) && (len < PRINTF_FTOA_BUFFER_SIZE)) {

     buf[len++] = '0';

   }

 

   // handle sign

+  if ((len == width) && (negative || (flags & FLAGS_PLUS) || (flags & FLAGS_SPACE))) {

+    len--;

+  }

   if (len < PRINTF_FTOA_BUFFER_SIZE) {

     if (negative) {

       buf[len++] = '-';

diff --git a/test/test_suite.cpp b/test/test_suite.cpp
index d990309..ab8f7e5 100644
--- a/test/test_suite.cpp
+++ b/test/test_suite.cpp
@@ -79,6 +79,12 @@ TEST_CASE("space flag", "[]" ) {
   test::sprintf(buffer, "% 15d", -42);

   REQUIRE(!strcmp(buffer, "            -42"));

 

+  test::sprintf(buffer, "% 15.3f", -42.987);

+  REQUIRE(!strcmp(buffer, "        -42.987"));

+

+  test::sprintf(buffer, "% 15.3f", 42.987);

+  REQUIRE(!strcmp(buffer, "         42.987"));

+

   test::sprintf(buffer, "% s", "Hello testing");

   REQUIRE(!strcmp(buffer, "Hello testing"));

 

@@ -211,6 +217,15 @@ TEST_CASE("0 flag", "[]" ) {
 

   test::sprintf(buffer, "%015d", -42);

   REQUIRE(!strcmp(buffer, "-00000000000042"));

+

+  test::sprintf(buffer, "%015.2f", 42.1234);

+  REQUIRE(!strcmp(buffer, "000000000042.12"));

+

+  test::sprintf(buffer, "%015.3f", 42.9876);

+  REQUIRE(!strcmp(buffer, "00000000042.988"));

+

+  test::sprintf(buffer, "%015.5f", -42.9876);

+  REQUIRE(!strcmp(buffer, "-00000042.98760"));

 }

 

 

@@ -485,6 +500,9 @@ TEST_CASE("width -20", "[]" ) {
   test::sprintf(buffer, "%-20u", 1024);

   REQUIRE(!strcmp(buffer, "1024                "));

 

+  test::sprintf(buffer, "%-20.4f", 1024.1234);

+  REQUIRE(!strcmp(buffer, "1024.1234           "));

+

   test::sprintf(buffer, "%-20u", 4294966272U);

   REQUIRE(!strcmp(buffer, "4294966272          "));