win32: stat(2): return correct st_blocks for compressed/sparse files

Use GetCompressedFileSize to obtain the actual number of blocks
for compressed or sparse files.  Use this to return a more accurate
value for st_blocks.

1 files changed, 13 insertions, 1 deletions

diff --git a/win32/mingw.c b/win32/mingw.c
index d6cd25107..894388b64 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -504,6 +504,8 @@ static int do_lstat(int follow, const char *file_name, struct mingw_stat *buf)
         int err = EINVAL;
         WIN32_FILE_ATTRIBUTE_DATA fdata;
         WIN32_FIND_DATAA findbuf;
+        DWORD low, high;
+        off64_t size;
 #if ENABLE_FEATURE_EXTRA_FILE_DATA
         DWORD flags;
         BY_HANDLE_FILE_INFORMATION hdata;
@@ -572,12 +574,22 @@ static int do_lstat(int follow, const char *file_name, struct mingw_stat *buf)
                 }
 #endif
 
+                /* Get actual size of compressed/sparse files */
+                low = GetCompressedFileSize(file_name, &high);
+                if ((low == INVALID_FILE_SIZE && GetLastError() != NO_ERROR) ||
+                                S_ISDIR(buf->st_mode)) {
+                        size = buf->st_size;
+                }
+                else {
+                        size = low | (((off64_t)high)<<32);
+                }
+
                 /*
                  * Assume a block is 4096 bytes and calculate number of 512 byte
                  * sectors.
                  */
                 buf->st_blksize = 4096;
-                buf->st_blocks = ((buf->st_size+4095)>>12)<<3;
+                buf->st_blocks = ((size+4095)>>12)<<3;
                 return 0;
         }
         errno = err;