fix fs.readFile with lying size=0 stat results

1 files changed, 60 insertions, 13 deletions

diff --git a/lib/fs.js b/lib/fs.js
index d6f195afe..6f8e3b736 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -108,7 +108,8 @@ fs.readFile = function(path, encoding_) {
 
   // first, stat the file, so we know the size.
   var size;
-  var buffer;
+  var buffer; // single buffer with file data
+  var buffers; // list for when size is unknown
   var pos = 0;
   var fd;
 
@@ -120,8 +121,10 @@ fs.readFile = function(path, encoding_) {
       if (er) return callback(er);
       size = st.size;
       if (size === 0) {
-        buffer = new Buffer(0);
-        return afterRead(null, 0);
+        // the kernel lies about many files.
+        // Go ahead and try to read some bytes.
+        buffers = [];
+        return read();
       }
 
       buffer = new Buffer(size);
@@ -130,7 +133,12 @@ fs.readFile = function(path, encoding_) {
   });
 
   function read() {
-    fs.read(fd, buffer, pos, size - pos, pos, afterRead);
+    if (size === 0) {
+      buffer = new Buffer(8192);
+      fs.read(fd, buffer, 0, 8192, pos, afterRead);
+    } else {
+      fs.read(fd, buffer, pos, size - pos, pos, afterRead);
+    }
   }
 
   function afterRead(er, bytesRead) {
@@ -141,12 +149,27 @@ fs.readFile = function(path, encoding_) {
     }
 
     pos += bytesRead;
-    if (pos === size) close();
-    else read();
+    if (size !== 0) {
+      if (pos === size) close();
+      else read();
+    } else {
+      // unknown size, just read until we don't get bytes.
+      if (bytesRead > 0) {
+        buffers.push(buffer.slice(0, bytesRead));
+        read();
+      } else {
+        close();
+      }
+    }
   }
 
   function close() {
     fs.close(fd, function(er) {
+      if (size === 0) {
+        // collected the data into the buffers list.
+        buffer = Buffer.concat(buffer.length, pos);
+      }
+
       if (encoding) buffer = buffer.toString(encoding);
       return callback(er, buffer);
     });
@@ -165,28 +188,52 @@ fs.readFileSync = function(path, encoding) {
     if (threw) fs.closeSync(fd);
   }
 
+  var pos = 0;
+  var buffer; // single buffer with file data
+  var buffers; // list for when size is unknown
+
   if (size === 0) {
-    fs.closeSync(fd);
-    return encoding ? '' : new Buffer(0);
+    buffers = [];
+  } else {
+    buffer = new Buffer(size);
   }
 
-  var buffer = new Buffer(size);
-  var pos = 0;
-
-  while (pos < size) {
+  var done = false;
+  while (!done) {
     var threw = true;
     try {
-      var bytesRead = fs.readSync(fd, buffer, pos, size - pos, pos);
+      if (size !== 0) {
+        var bytesRead = fs.readSync(fd, buffer, pos, size - pos, pos);
+      } else {
+        // the kernel lies about many files.
+        // Go ahead and try to read some bytes.
+        buffer = new Buffer(8192);
+        var bytesRead = fs.readSync(fd, buffer, 0, 8192, pos);
+        if (bytesRead) {
+          buffers.push(buffer.slice(0, bytesRead));
+        }
+      }
       threw = false;
     } finally {
       if (threw) fs.closeSync(fd);
     }
 
     pos += bytesRead;
+
+    if (size !== 0) {
+      done = pos >= size;
+    } else {
+      done = bytesRead > 0;
+    }
   }
 
   fs.closeSync(fd);
 
+  if (size === 0) {
+    // data was collected into the buffers list.
+    buffer = Buffer.concat(buffers, pos);
+  }
+
   if (encoding) buffer = buffer.toString(encoding);
   return buffer;
 };