1 files changed, 10 insertions, 8 deletions
diff --git a/mrbgems/mruby-sprintf/src/sprintf.c b/mrbgems/mruby-sprintf/src/sprintf.c
index 080e2549d..8df0d9360 100644
--- a/mrbgems/mruby-sprintf/src/sprintf.c
+++ b/mrbgems/mruby-sprintf/src/sprintf.c
@@ -982,15 +982,17 @@ retry:
         }
         if (dots) PUSH("..", 2);
 
-        if (v < 0) {
-          char c = sign_bits(base, p);
-          FILL(c, prec - len);
-        }
-        else if ((flags & (FMINUS|FPREC)) != FMINUS) {
-          char c = '0';
-          FILL(c, prec - len);
+        if (prec > len) {
+          CHECK(prec - len);
+          if (v < 0) {
+            char c = sign_bits(base, p);
+            FILL(c, prec - len);
+          }
+          else if ((flags & (FMINUS|FPREC)) != FMINUS) {
+            char c = '0';
+            FILL(c, prec - len);
+          }
         }
-
         PUSH(s, len);
         if (width > 0) {
           FILL(' ', width);