From ead4f122e41cf3cc1af1719778da1070cee1d797 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Thu, 29 Dec 2022 20:42:07 -0800
Subject: [PATCH] Added basic support for %g snprintf format specifier
---
src/stdlib/SDL_string.c | 31 +++++++++++++++++++++++++++++++
test/testautomation_stdlib.c | 12 ++++++++++++
2 files changed, 43 insertions(+)
diff --git a/src/stdlib/SDL_string.c b/src/stdlib/SDL_string.c
index e6464da631a7..047dd572749c 100644
--- a/src/stdlib/SDL_string.c
+++ b/src/stdlib/SDL_string.c
@@ -1675,6 +1675,29 @@ SDL_PrintFloat(char *text, size_t maxlen, SDL_FormatInfo *info, double arg)
return length;
}
+static size_t
+SDL_TrimTrailingFractionalZeroes(char *text, size_t start, size_t length)
+{
+ size_t i, j;
+
+ for (i = start; i < length; ++i) {
+ if (text[i] == '.' || text[i] == ',') {
+ for (j = length - 1; j > i; --j) {
+ if (text[j] == '0') {
+ --length;
+ } else {
+ break;
+ }
+ }
+ if (j == i) {
+ --length;
+ }
+ break;
+ }
+ }
+ return length;
+}
+
/* NOLINTNEXTLINE(readability-non-const-parameter) */
int SDL_vsnprintf(SDL_OUT_Z_CAP(maxlen) char *text, size_t maxlen, const char *fmt, va_list ap)
{
@@ -1856,6 +1879,14 @@ int SDL_vsnprintf(SDL_OUT_Z_CAP(maxlen) char *text, size_t maxlen, const char *f
length += SDL_PrintFloat(TEXT_AND_LEN_ARGS, &info, va_arg(ap, double));
done = SDL_TRUE;
break;
+ case 'g':
+ {
+ size_t starting_length = length;
+ length += SDL_PrintFloat(TEXT_AND_LEN_ARGS, &info, va_arg(ap, double));
+ length = SDL_TrimTrailingFractionalZeroes(text, starting_length, length);
+ done = SDL_TRUE;
+ break;
+ }
case 'S':
{
/* In practice this is used on Windows for WCHAR strings */
diff --git a/test/testautomation_stdlib.c b/test/testautomation_stdlib.c
index f818e7a0f458..2d2ed0fdabe4 100644
--- a/test/testautomation_stdlib.c
+++ b/test/testautomation_stdlib.c
@@ -153,6 +153,18 @@ int stdlib_snprintf(void *arg)
SDLTest_AssertCheck(SDL_strcmp(text, expected) == 0, "Check text, expected: '%s', got: '%s'", expected, text);
SDLTest_AssertCheck(result == 6, "Check result value, expected: 6, got: %d", result);
+ result = SDL_snprintf(text, sizeof(text), "%g", 100.0);
+ expected = "100";
+ SDLTest_AssertPass("Call to SDL_snprintf(\"%%g\", 100.0)");
+ SDLTest_AssertCheck(SDL_strcmp(text, expected) == 0, "Check text, expected: '%s', got: '%s'", expected, text);
+ SDLTest_AssertCheck(result == 3, "Check result value, expected: 3, got: %d", result);
+
+ result = SDL_snprintf(text, sizeof(text), "%g", 100.75);
+ expected = "100.75";
+ SDLTest_AssertPass("Call to SDL_snprintf(\"%%g\", 100.75)");
+ SDLTest_AssertCheck(SDL_strcmp(text, expected) == 0, "Check text, expected: '%s', got: '%s'", expected, text);
+ SDLTest_AssertCheck(result == 6, "Check result value, expected: 6, got: %d", result);
+
size = 64;
result = SDL_snprintf(text, sizeof(text), "%zu %s", size, "test");
expected = "64 test";