Close file descriptors when exception is raised (#18)

Closes: #17

gzip.ml

@@ -74,7 +74,11 @@ let open_in_chan ic =
     in_crc = Int32.zero }
 
 let open_in filename =
-  open_in_chan (Pervasives.open_in_bin filename)
+  let ic = Pervasives.open_in_bin filename in
+  try 
+    open_in_chan ic
+  with exn ->
+    Pervasives.close_in ic; raise exn
 
 let read_byte iz =
   if iz.in_avail = 0 then begin

zip.ml

@@ -131,8 +131,8 @@ let read_ecd filename ic =
     let newlen = min (toread + len) 256 in
     (* Search for magic number *)
     let ofs = strrstr "PK\005\006" buf 0 newlen in
-    if ofs < 0 || newlen < 22 || 
-       (let comment_len = 
+    if ofs < 0 || newlen < 22 ||
+       (let comment_len =
               (Char.code (Bytes.get buf (ofs + 20)))
           lor ((Char.code (Bytes.get buf (ofs + 21))) lsl 8) in
         Int64.(add newpos (of_int (ofs + 22 + comment_len))) <> filelen) then
@@ -219,16 +219,19 @@ let read_cd filename ic cd_entries cd_offset cd_bound =
 
 let open_in filename =
   let ic = Pervasives.open_in_bin filename in
-  let (cd_entries, cd_size, cd_offset, cd_comment) = read_ecd filename ic in
-  let entries =
-    read_cd filename ic cd_entries cd_offset (Int32.add cd_offset cd_size) in
-  let dir = Hashtbl.create (cd_entries / 3) in
-  List.iter (fun e -> Hashtbl.add dir e.filename e) entries;
-  { if_filename = filename;
-    if_channel = ic;
-    if_entries = entries;
-    if_directory = dir;
-    if_comment = cd_comment }
+  try
+    let (cd_entries, cd_size, cd_offset, cd_comment) = read_ecd filename ic in
+    let entries =
+      read_cd filename ic cd_entries cd_offset (Int32.add cd_offset cd_size) in
+    let dir = Hashtbl.create (cd_entries / 3) in
+    List.iter (fun e -> Hashtbl.add dir e.filename e) entries;
+    { if_filename = filename;
+      if_channel = ic;
+      if_entries = entries;
+      if_directory = dir;
+      if_comment = cd_comment }
+  with exn ->
+    Pervasives.close_in ic; raise exn
 
 (* Close a ZIP file opened for reading *)
 
@@ -307,7 +310,7 @@ let read_entry ifile e =
         Bytes.unsafe_to_string res
   with End_of_file ->
     raise (Error(ifile.if_filename, e.filename, "truncated data"))
-    
+
 (* Write the contents of an entry into an out channel *)
 
 let copy_entry_to_channel ifile e oc =
@@ -346,7 +349,7 @@ let copy_entry_to_channel ifile e oc =
           raise (Error(ifile.if_filename, e.filename, "CRC mismatch"))
   with End_of_file ->
     raise (Error(ifile.if_filename, e.filename, "truncated data"))
-    
+
 (* Write the contents of an entry to a file *)
 
 let copy_entry_to_file ifile e outfilename =
@@ -471,7 +474,7 @@ let add_data_descriptor ofile crc compr_size uncompr_size entry =
 
 (* Add an entry with the contents of a string *)
 
-let add_entry data ofile ?(extra = "") ?(comment = "") 
+let add_entry data ofile ?(extra = "") ?(comment = "")
                          ?(level = 6) ?(mtime = Unix.time()) name =
   let e = add_entry_header ofile extra comment level mtime name in
   let crc = Zlib.update_crc_string Int32.zero data 0 (String.length data) in
@@ -502,7 +505,7 @@ let add_entry data ofile ?(extra = "") ?(comment = "")
 
 (* Add an entry with the contents of an in channel *)
 
-let copy_channel_to_entry ic ofile ?(extra = "") ?(comment = "") 
+let copy_channel_to_entry ic ofile ?(extra = "") ?(comment = "")
                                    ?(level = 6) ?(mtime = Unix.time()) name =
   let e = add_entry_header ofile extra comment level mtime name in
   let crc = ref Int32.zero in
@@ -529,7 +532,7 @@ let copy_channel_to_entry ic ofile ?(extra = "") ?(comment = "")
                crc := Zlib.update_crc !crc buf 0 r;
                in_pos := !in_pos + r;
                r)
-            (fun buf n ->            
+            (fun buf n ->
                output ofile.of_channel buf 0 n;
                out_pos := !out_pos + n);
           (!out_pos, !in_pos)
@@ -540,11 +543,11 @@ let copy_channel_to_entry ic ofile ?(extra = "") ?(comment = "")
 
 (* Add an entry with the contents of a file *)
 
-let copy_file_to_entry infilename ofile ?(extra = "") ?(comment = "") 
+let copy_file_to_entry infilename ofile ?(extra = "") ?(comment = "")
                                         ?(level = 6) ?mtime name =
   let ic = open_in_bin infilename in
   let mtime' =
-    match mtime with 
+    match mtime with
       Some t -> mtime
     | None ->
         try Some((Unix.stat infilename).Unix.st_mtime)