duplicate current dir name in smc_save_yourself_CB

[bpt/emacs.git] / src / decompress.c

diff --git a/src/decompress.c b/src/decompress.c
index 4e4e3a9..cd8a3d1 100644 (file)
--- a/src/decompress.c
+++ b/src/decompress.c
@@ -1,5 +1,5 @@
 /* Interface to zlib.
-   Copyright (C) 2013 Free Software Foundation, Inc.
+   Copyright (C) 2013-2014 Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
 
@@ -26,6 +26,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "character.h"
 #include "buffer.h"
 
+#include <verify.h>
+
 static Lisp_Object Qzlib_dll;
 
 #ifdef WINDOWSNT
@@ -38,7 +40,7 @@ static Lisp_Object Qzlib_dll;
 /* Macro for loading zlib functions from the library.  */
 #define LOAD_ZLIB_FN(lib,func) {                                       \
     fn_##func = (void *) GetProcAddress (lib, #func);                  \
-    if (!fn_##func) return 0;                                          \
+    if (!fn_##func) return false;                                      \
   }
 
 DEF_ZLIB_FN (int, inflateInit2_,
@@ -50,6 +52,8 @@ DEF_ZLIB_FN (int, inflate,
 DEF_ZLIB_FN (int, inflateEnd,
             (z_streamp strm));
 
+static bool zlib_initialized;
+
 static bool
 init_zlib_functions (void)
 {
@@ -58,13 +62,13 @@ init_zlib_functions (void)
   if (!library)
     {
       message1 ("zlib library not found");
-      return 0;
+      return false;
     }
 
   LOAD_ZLIB_FN (library, inflateInit2_);
   LOAD_ZLIB_FN (library, inflate);
   LOAD_ZLIB_FN (library, inflateEnd);
-  return 1;
+  return true;
 }
 
 #define fn_inflateInit2(strm, windowBits) \
@@ -81,7 +85,7 @@ init_zlib_functions (void)
 \f
 struct decompress_unwind_data
 {
-  ptrdiff_t old_point, start;
+  ptrdiff_t old_point, start, nbytes;
   z_stream *stream;
 };
 
@@ -91,12 +95,14 @@ unwind_decompress (void *ddata)
   struct decompress_unwind_data *data = ddata;
   fn_inflateEnd (data->stream);
 
-  /* Delete any uncompressed data already inserted and restore point.  */
+  /* Delete any uncompressed data already inserted on error.  */
   if (data->start)
-    {
-      del_range (data->start, PT);
-      SET_PT (data->old_point);
-    }
+    del_range (data->start, data->start + data->nbytes);
+
+  /* Put point where it was, or if the buffer has shrunk because the
+     compressed data is bigger than the uncompressed, at
+     point-max.  */
+  SET_PT (min (data->old_point, ZV));
 }
 
 DEFUN ("zlib-available-p", Fzlib_available_p, Szlib_available_p, 0, 0, 0,
@@ -110,7 +116,8 @@ DEFUN ("zlib-available-p", Fzlib_available_p, Szlib_available_p, 0, 0, 0,
   else
     {
       Lisp_Object status;
-      status = init_zlib_functions () ? Qt : Qnil;
+      zlib_initialized = init_zlib_functions ();
+      status = zlib_initialized ? Qt : Qnil;
       Vlibrary_cache = Fcons (Fcons (Qzlib_dll, status), Vlibrary_cache);
       return status;
     }
@@ -119,10 +126,10 @@ DEFUN ("zlib-available-p", Fzlib_available_p, Szlib_available_p, 0, 0, 0,
 #endif
 }
 
-DEFUN ("zlib-decompress-gzipped-region", Fzlib_decompress_gzipped_region,
-       Szlib_decompress_gzipped_region,
+DEFUN ("zlib-decompress-region", Fzlib_decompress_region,
+       Szlib_decompress_region,
        2, 2, 0,
-       doc: /* Decompress a gzip-compressed region.
+       doc: /* Decompress a gzip- or zlib-compressed region.
 Replace the text in the region by the decompressed data.
 On failure, return nil and leave the data in place.
 This function can be called only in unibyte buffers.  */)
@@ -139,6 +146,13 @@ This function can be called only in unibyte buffers.  */)
   if (! NILP (BVAR (current_buffer, enable_multibyte_characters)))
     error ("This function can be called only in unibyte buffers");
 
+#ifdef WINDOWSNT
+  if (!zlib_initialized)
+    zlib_initialized = init_zlib_functions ();
+  if (!zlib_initialized)
+    return Qnil;
+#endif
+
   /* This is a unibyte buffer, so character positions and bytes are
      the same.  */
   istart = XINT (start);
@@ -151,14 +165,15 @@ This function can be called only in unibyte buffers.  */)
   stream.avail_in = 0;
   stream.next_in = Z_NULL;
 
-  /* This magic number apparently means "this is gzip".  */
-  if (fn_inflateInit2 (&stream, 16 + MAX_WBITS) != Z_OK)
+  /* The magic number 32 apparently means "autodetect both the gzip and
+     zlib formats" according to zlib.h.  */
+  if (fn_inflateInit2 (&stream, MAX_WBITS + 32) != Z_OK)
     return Qnil;
 
   unwind_data.start = iend;
   unwind_data.stream = &stream;
   unwind_data.old_point = PT;
-
+  unwind_data.nbytes = 0;
   record_unwind_protect_ptr (unwind_decompress, &unwind_data);
 
   /* Insert the decompressed data at the end of the compressed data.  */
@@ -170,12 +185,11 @@ This function can be called only in unibyte buffers.  */)
   do
     {
       /* Maximum number of bytes that one 'inflate' call should read and write.
-        zlib requires that these values not exceed UINT_MAX.
-        Do not make avail_out too large, as that might unduly delay C-g.  */
+        Do not make avail_out too large, as that might unduly delay C-g.
+        zlib requires that avail_in and avail_out not exceed UINT_MAX.  */
       ptrdiff_t avail_in = min (iend - pos_byte, UINT_MAX);
-      ptrdiff_t avail_out = min (1 << 14, UINT_MAX);
-
-      ptrdiff_t decompressed;
+      int avail_out = 16 * 1024;
+      int decompressed;
 
       if (GAP_SIZE < avail_out)
        make_gap (avail_out - GAP_SIZE);
@@ -187,6 +201,7 @@ This function can be called only in unibyte buffers.  */)
       pos_byte += avail_in - stream.avail_in;
       decompressed = avail_out - stream.avail_out;
       insert_from_gap (decompressed, decompressed, 0);
+      unwind_data.nbytes += decompressed;
       QUIT;
     }
   while (inflate_status == Z_OK);
@@ -210,7 +225,7 @@ void
 syms_of_decompress (void)
 {
   DEFSYM (Qzlib_dll, "zlib");
-  defsubr (&Szlib_decompress_gzipped_region);
+  defsubr (&Szlib_decompress_region);
   defsubr (&Szlib_available_p);
 }