fix(printf): fix broken right-padding in _ftoa

Fixes #24

2 files changed, 9 insertions, 1 deletions

diff --git a/printf.c b/printf.c
index e4c83e5..50af893 100644
--- a/printf.c
+++ b/printf.c
@@ -262,6 +262,8 @@ static size_t _ntoa_long_long(out_fct_type out, char* buffer, size_t idx, size_t
 #if defined(PRINTF_SUPPORT_FLOAT)

 static size_t _ftoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags)

 {

+  const size_t start_idx = idx;

+

   char buf[PRINTF_FTOA_BUFFER_SIZE];

   size_t len  = 0U;

   double diff = 0.0;

@@ -388,7 +390,7 @@ static size_t _ftoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, d
 

   // append pad spaces up to given width

   if (flags & FLAGS_LEFT) {

-    while (idx < width) {

+    while (idx - start_idx < width) {

       out(' ', buffer, idx++, maxlen);

     }

   }

diff --git a/test/test_suite.cpp b/test/test_suite.cpp
index 3ecac5f..05b95f7 100644
--- a/test/test_suite.cpp
+++ b/test/test_suite.cpp
@@ -990,6 +990,12 @@ TEST_CASE("float", "[]" ) {
   test::sprintf(buffer, "%.1f", 3.49);

   REQUIRE(!strcmp(buffer, "3.5"));

 

+  test::sprintf(buffer, "a%-5.1f", 0.5);

+  REQUIRE(!strcmp(buffer, "a0.5  "));

+

+  test::sprintf(buffer, "a%-5.1fend", 0.5);

+  REQUIRE(!strcmp(buffer, "a0.5  end"));

+

   // out of range in the moment, need to be fixed by someone

   test::sprintf(buffer, "%.1f", 1E20);

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