backport r13488

svn:r13489

ChangeLog

@@ -13,6 +13,8 @@ Changes in versino 0.1.2.20 - 2008-??-??
       Resolves bug 597.
     - Fix a few memory leaks that could in theory happen under bizarre error
       conditions.
+    - We were leaking a file descriptor if Tor started with a zero-length
+      cached-descriptors file. Patch by freddy77.
 
 
 Changes in version 0.1.2.19 - 2008-01-17

src/common/compat.c

@@ -158,19 +158,18 @@ tor_mmap_file(const char *filename)
     /* Zero-length file. If we call mmap on it, it will succeed but
      * return NULL, and bad things will happen. So just fail. */
     log_info(LD_FS,"File \"%s\" is empty. Ignoring.",filename);
+    close(fd);
     return NULL;
   }
 
   string = mmap(0, size, PROT_READ, MAP_PRIVATE, fd, 0);
+  close(fd);
   if (string == MAP_FAILED) {
-    close(fd);
     log_warn(LD_FS,"Could not mmap file \"%s\": %s", filename,
              strerror(errno));
     return NULL;
   }
 
-  close(fd);
-
   res = tor_malloc_zero(sizeof(tor_mmap_impl_t));
   res->base.data = string;
   res->base.size = filesize;