Fix handling negative screen filters values

arm9/source/config.c

@@ -142,21 +142,47 @@ static int parseDecIntOption(s64 *out, const char *val, s64 minval, s64 maxval)
 
 static int parseDecFloatOption(s64 *out, const char *val, s64 minval, s64 maxval)
 {
-    char *point = strchrnul(val, '.');
+    s64 sign = 1;// intPart < 0 ? -1 : 1;
-    if (point == val) {
+
+    switch (val[0]) {
+        case '\0':
+            return -1;
+        case '+':
+            ++val;
+            break;
+        case '-':
+            sign = -1;
+            ++val;
+            break;
+        default:
+            break;
+    }
+
+    // Reject "-" and "+"
+    if (val[0] == '\0') {
         return -1;
     }
 
+    char *point = strchrnul(val, '.');
+
     // Parse integer part, then fractional part
     s64 intPart = 0;
     s64 fracPart = 0;
-    int rc = parseDecIntOptionImpl(&intPart, val, point - val, INT64_MIN, INT64_MAX);
+    int rc = 0;
+
+    if (point == val) {
+        // e.g. -.5
+        if (val[1] == '\0')
+            return -1;
+    }
+    else {
+        rc = parseDecIntOptionImpl(&intPart, val, point - val, INT64_MIN, INT64_MAX);
+    }
 
     if (rc != 0) {
         return -1;
     }
 
-    s64 sign = intPart < 0 ? -1 : 1;
     s64 intPartAbs = sign == -1 ? -intPart : intPart;
     s64 res = 0;
     bool of = __builtin_mul_overflow(intPartAbs, FLOAT_CONV_MULT, &res);

sysmodules/rosalina/source/utils.c

@@ -179,8 +179,8 @@ int floatToString(char *out, float f, u32 precision, bool pad)
 
     u64 mult = pow10[precision];
     double f2 = fabs((double)f) * mult + 0.5;
-    const char *sign = f2 >= 0.0f ? "" : "-";
     u64 f3 = (u64)f2;
+    const char *sign = (f >= 0.0f || f3 == 0) ? "" : "-";
 
     u64 intPart = f3 / mult;
     u64 fracPart = f3 % mult;