Fix behavior strndup whern size <= 0, in this case strndup returns empty string

2 files changed, 20 insertions, 8 deletions

diff --git a/src/library.js b/src/library.js
index c353380c..8d68251f 100644
--- a/src/library.js
+++ b/src/library.js
@@ -4203,8 +4203,12 @@ LibraryManager.library = {
   strndup: function(ptr, size) {
     var len = String_len(ptr);
 
-    if (size <= 0 || size >= len) {
-       return _strdup(ptr);
+    if (size >= len) {
+      return _strdup(ptr);
+    }
+
+    if (size < 0) {
+      size = 0;
     }
     
     var newStr = _malloc(size + 1);
diff --git a/tests/runner.py b/tests/runner.py
index 4064af15..cc3811a2 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -1406,26 +1406,34 @@ m_divisor is 1091269979
           int main(int argc, char **argv) {
             const char* source = "strndup - duplicate a specific number of bytes from a string";
 
-            char* strdup_val = strndup(source, 7);
-            printf("%s\\n", strdup_val);
+            char* strdup_val = strndup(source, 0);
+            printf("1:%s\\n", strdup_val);
+            free(strdup_val);
+
+            strdup_val = strndup(source, 7);
+            printf("2:%s\\n", strdup_val);
             free(strdup_val);
 
             strdup_val = strndup(source, 1000);
-            printf("%s\\n", strdup_val);
+            printf("3:%s\\n", strdup_val);
             free(strdup_val);
 
             strdup_val = strndup(source, 60);
-            printf("%s\\n", strdup_val);
+            printf("4:%s\\n", strdup_val);
             free(strdup_val);
 
             strdup_val = strndup(source, 19);
-            printf("%s\\n", strdup_val);
+            printf("5:%s\\n", strdup_val);
+            free(strdup_val);
+
+            strdup_val = strndup(source, -1);
+            printf("6:%s\\n", strdup_val);
             free(strdup_val);
 
             return 0;
           }
         '''
-        self.do_run(src, 'strndup\nstrndup - duplicate a specific number of bytes from a string\nstrndup - duplicate a specific number of bytes from a string\nstrndup - duplicate\n')
+        self.do_run(src, '1:\n2:strndup\n3:strndup - duplicate a specific number of bytes from a string\n4:strndup - duplicate a specific number of bytes from a string\n5:strndup - duplicate\n6:\n')
 
     def test_errar(self):
         src = r'''