remove leading zeros in %llx

2 files changed, 38 insertions, 1 deletions

diff --git a/src/library.js b/src/library.js
index 18f4702c..51921541 100644
--- a/src/library.js
+++ b/src/library.js
@@ -2821,7 +2821,9 @@ LibraryManager.library = {
           } else if (next == {{{ charCode('x') }}} || next == {{{ charCode('X') }}}) {
             prefix = flagAlternative ? '0x' : '';
 #if PRECISE_I64_MATH
-            if (argSize == 8 && i64Math) argText = (origArg[1]>>>0).toString(16) + (origArg[0]>>>0).toString(16); else
+            if (argSize == 8 && i64Math) {
+              argText = (origArg[1] ? (origArg[1]>>>0).toString(16) : '') + (origArg[0]>>>0).toString(16);
+            } else
 #endif
             if (currArg < 0) {
               // Represent negative numbers in hex as 2's complement.
diff --git a/tests/runner.py b/tests/runner.py
index 7f46dbfb..ff44e388 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -5253,6 +5253,41 @@ at function.:blag
         '''
       self.do_run(src, re.sub('(^|\n)\s+', '\\1', expected))
 
+    def test_vsnprintf(self):
+      src = r'''
+        #include <stdio.h>
+        #include <stdarg.h>
+        #include <stdint.h>
+
+        void printy(const char *f, ...)
+        {
+          char buffer[256];
+          va_list args;
+          va_start(args, f);
+          vsnprintf(buffer, 256, f, args);
+          puts(buffer);
+          va_end(args);
+        }
+
+        int main(int argc, char **argv) {
+          int64_t x = argc - 1;
+          int64_t y = argc - 1 + 0x400000;
+          if (x % 3 == 2) y *= 2;
+
+          printy("0x%llx_0x%llx", x, y);
+          printy("0x%llx_0x%llx", x, x);
+          printy("0x%llx_0x%llx", y, x);
+          printy("0x%llx_0x%llx", y, y);
+
+          return 0;
+        }
+      '''
+      self.do_run(src, '''0x0_0x400000
+0x0_0x0
+0x400000_0x0
+0x400000_0x400000
+''')
+
     def test_printf_more(self):
       src = r'''
         #include <stdio.h>