handle malloc(0) and free(0) in corruption checker

2 files changed, 41 insertions, 1 deletions

diff --git a/src/corruptionCheck.js b/src/corruptionCheck.js
index ae2a0bdf..bd3b240b 100644
--- a/src/corruptionCheck.js
+++ b/src/corruptionCheck.js
@@ -19,8 +19,8 @@ var CorruptionChecker = {
     } });
   },
   malloc: function(size) {
+    if (size <= 0) size = 1; // malloc(0) sometimes happens - just allocate a larger area, no harm
     CorruptionChecker.checkAll();
-    assert(size > 0); // some mallocs accept zero - fix your code if you want to use this tool
     size = (size+7)&(~7);
     var allocation = CorruptionChecker.realMalloc(size*(1+2*CorruptionChecker.BUFFER_FACTOR));
     var ptr = allocation + size*CorruptionChecker.BUFFER_FACTOR;
@@ -28,13 +28,17 @@ var CorruptionChecker = {
     CorruptionChecker.ptrs[ptr] = size;
     CorruptionChecker.fillBuffer(allocation, size*CorruptionChecker.BUFFER_FACTOR);
     CorruptionChecker.fillBuffer(allocation + size*(1+CorruptionChecker.BUFFER_FACTOR), size*CorruptionChecker.BUFFER_FACTOR);
+    //Module.print('malloc ' + size + ' ==> ' + [ptr, allocation]);
     return ptr;
   },
   free: function(ptr) {
+    if (!ptr) return; // ok to free(NULL), does nothing
     CorruptionChecker.checkAll();
     var size = CorruptionChecker.ptrs[ptr];
+    //Module.print('free ' + ptr + ' of size ' + size);
     assert(size);
     var allocation = ptr - size*CorruptionChecker.BUFFER_FACTOR;
+    //Module.print('free ' + ptr + ' of size ' + size + ' and allocation ' + allocation);
     delete CorruptionChecker.ptrs[ptr];
     CorruptionChecker.realFree(allocation);
   },
diff --git a/tests/runner.py b/tests/runner.py
index a2d75cfe..f0340cd0 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -7214,6 +7214,42 @@ def process(filename):
       for corrupt in [1]:
         self.do_run(src.replace('CORRUPT', str(corrupt)), 'Heap corruption detected!' if corrupt else 'All ok, 4209')
 
+    def test_corruption_2(self):
+      if Settings.ASM_JS: return self.skip('cannot use corruption checks in asm')
+      if Settings.USE_TYPED_ARRAYS != 2: return self.skip('needs ta2 for actual test')
+
+      Settings.SAFE_HEAP = 1
+      Settings.CORRUPTION_CHECK = 1
+
+      # test for free(0), malloc(0), etc.
+      src = r'''
+        #include <iostream>
+        #include <fstream>
+        #include <stdlib.h>
+        #include <stdio.h>
+
+        void bye() {
+          printf("all ok\n");
+        }
+
+        int main() {
+          atexit(bye);
+
+          std::string testPath = "/Script/WA-KA.txt";
+          std::fstream str(testPath.c_str(), std::ios::in | std::ios::binary);
+
+          if (str.is_open())
+          {
+            std::cout << "open!" << std::endl;
+          } else {
+            std::cout << "missing!" << std::endl;
+          }
+
+          return 1;
+        }
+        '''
+      self.do_run(src, 'missing!\nall ok\n')
+
     ### Integration tests
 
     def test_ccall(self):