grep: move logic to compile header pattern into a separate helper

diff --git a/compat/mingw.c b/compat/mingw.c
index 754b5340b087841aaa7601c784c8ca9f15ed64a6..f2d9e1fd974b7271366da09370e10fafd2c50f08 100644 (file)
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -140,6 +140,39 @@ int mingw_open (const char *filename, int oflags, ...)
        return fd;
 }
 
+#undef write
+ssize_t mingw_write(int fd, const void *buf, size_t count)
+{
+       /*
+        * While write() calls to a file on a local disk are translated
+        * into WriteFile() calls with a maximum size of 64KB on Windows
+        * XP and 256KB on Vista, no such cap is placed on writes to
+        * files over the network on Windows XP.  Unfortunately, there
+        * seems to be a limit of 32MB-28KB on X64 and 64MB-32KB on x86;
+        * bigger writes fail on Windows XP.
+        * So we cap to a nice 31MB here to avoid write failures over
+        * the net without changing the number of WriteFile() calls in
+        * the local case.
+        */
+       return write(fd, buf, min(count, 31 * 1024 * 1024));
+}
+
+#undef fopen
+FILE *mingw_fopen (const char *filename, const char *otype)
+{
+       if (!strcmp(filename, "/dev/null"))
+               filename = "nul";
+       return fopen(filename, otype);
+}
+
+#undef freopen
+FILE *mingw_freopen (const char *filename, const char *otype, FILE *stream)
+{
+       if (filename && !strcmp(filename, "/dev/null"))
+               filename = "nul";
+       return freopen(filename, otype, stream);
+}
+
 /*
  * The unit of FILETIME is 100-nanoseconds since January 1, 1601, UTC.
  * Returns the 100-nanoseconds ("hekto nanoseconds") since the epoch.
@@ -259,17 +292,38 @@ int mingw_utime (const char *file_name, const struct utimbuf *times)
        int fh, rc;
 
        /* must have write permission */
-       if ((fh = open(file_name, O_RDWR | O_BINARY)) < 0)
-               return -1;
+       DWORD attrs = GetFileAttributes(file_name);
+       if (attrs != INVALID_FILE_ATTRIBUTES &&
+           (attrs & FILE_ATTRIBUTE_READONLY)) {
+               /* ignore errors here; open() will report them */
+               SetFileAttributes(file_name, attrs & ~FILE_ATTRIBUTE_READONLY);
+       }
 
-       time_t_to_filetime(times->modtime, &mft);
-       time_t_to_filetime(times->actime, &aft);
+       if ((fh = open(file_name, O_RDWR | O_BINARY)) < 0) {
+               rc = -1;
+               goto revert_attrs;
+       }
+
+       if (times) {
+               time_t_to_filetime(times->modtime, &mft);
+               time_t_to_filetime(times->actime, &aft);
+       } else {
+               GetSystemTimeAsFileTime(&mft);
+               aft = mft;
+       }
        if (!SetFileTime((HANDLE)_get_osfhandle(fh), NULL, &aft, &mft)) {
                errno = EINVAL;
                rc = -1;
        } else
                rc = 0;
        close(fh);
+
+revert_attrs:
+       if (attrs != INVALID_FILE_ATTRIBUTES &&
+           (attrs & FILE_ATTRIBUTE_READONLY)) {
+               /* ignore errors again */
+               SetFileAttributes(file_name, attrs);
+       }
        return rc;
 }
 
@@ -592,7 +646,7 @@ static char *lookup_prog(const char *dir, const char *cmd, int isexe, int exe_on
 }
 
 /*
- * Determines the absolute path of cmd using the the split path in path.
+ * Determines the absolute path of cmd using the split path in path.
  * If cmd contains a slash or backslash, no lookup is performed.
  */
 static char *path_lookup(const char *cmd, char **path, int exe_only)