Commit ee3c83f3 authored by Jay Satiro's avatar Jay Satiro
Browse files

tool_operate: Fix --remote-time incorrect times on Windows 

- Use Windows API SetFileTime to set the file time instead of utime.

Avoid utime on Windows if possible because it may apply a daylight
saving time offset to our UTC file time.

Bug: https://curl.haxx.se/mail/archive-2016-11/0033.html
Reported-by: Tim

Closes https://github.com/curl/curl/pull/1121
parent 89b78988

docs/FAQ

+6 −4
Original line number Diff line number Diff line
@@ -1016,10 +1016,12 @@ FAQ 


  4.13 Why is curl -R on Windows one hour off?



  During daylight savings time, when -R is used, curl will set a time that

  appears one hour off. This happens due to a flaw in how Windows stores and

  uses file modification times and it is not easily worked around. For details

  on this problem, read this: http://www.codeproject.com/datetime/dstbugs.asp

  Since curl 7.53.0 this issue should be fixed as long as curl was built with

  any modern compiler that allows for a 64-bit curl_off_t type. For older

  compilers or prior curl versions it may set a time that appears one hour off.

  This happens due to a flaw in how Windows stores and uses file modification

  times and it is not easily worked around. For more details read this:

  http://www.codeproject.com/datetime/dstbugs.asp



  4.14 Redirects work in browser but not with curl!

src/tool_operate.c

+48 −3
Original line number Diff line number Diff line
@@ -1727,20 +1727,65 @@ static CURLcode operate_do(struct GlobalConfig *global, 
        }

#endif



#ifdef HAVE_UTIME

#if defined(HAVE_UTIME) || \

    (defined(WIN32) && (CURL_SIZEOF_CURL_OFF_T >= 8))

        /* File time can only be set _after_ the file has been closed */

        if(!result && config->remote_time && outs.s_isreg && outs.filename) {

          /* Ask libcurl if we got a remote file time */

          long filetime = -1;

          curl_easy_getinfo(curl, CURLINFO_FILETIME, &filetime);

          if(filetime >= 0) {

/* Windows utime() may attempt to adjust our unix gmt 'filetime' by a daylight

   saving time offset and since it's GMT that is bad behavior. When we have

   access to a 64-bit type we can bypass utime and set the times directly. */

#if defined(WIN32) && (CURL_SIZEOF_CURL_OFF_T >= 8)

            /* 910670515199 is the maximum unix filetime that can be used as a

               Windows FILETIME without overflow: 30827-12-31T23:59:59. */

            if(filetime <= CURL_OFF_T_C(910670515199)) {

              HANDLE hfile = CreateFileA(outs.filename, FILE_WRITE_ATTRIBUTES,

                                         (FILE_SHARE_READ | FILE_SHARE_WRITE |

                                          FILE_SHARE_DELETE),

                                         NULL, OPEN_EXISTING, 0, NULL);

              if(hfile != INVALID_HANDLE_VALUE) {

                curl_off_t converted = ((curl_off_t)filetime * 10000000) +

                                       CURL_OFF_T_C(116444736000000000);

                FILETIME ft;

                ft.dwLowDateTime = (DWORD)(converted & 0xFFFFFFFF);

                ft.dwHighDateTime = (DWORD)(converted >> 32);

                if(!SetFileTime(hfile, NULL, &ft, &ft)) {

                  fprintf(config->global->errors,

                          "Failed to set filetime %ld on outfile: "

                          "SetFileTime failed: GetLastError %u\n",

                          filetime, GetLastError());

                }

                CloseHandle(hfile);

              }

              else {

                fprintf(config->global->errors,

                        "Failed to set filetime %ld on outfile: "

                        "CreateFile failed: GetLastError %u\n",

                        filetime, GetLastError());

              }

            }

            else {

              fprintf(config->global->errors,

                      "Failed to set filetime %ld on outfile: overflow\n",

                      filetime);

            }

#elif defined(HAVE_UTIME)

            struct utimbuf times;

            times.actime = (time_t)filetime;

            times.modtime = (time_t)filetime;

            utime(outs.filename, &times); /* set the time we got */

          }

            if(utime(outs.filename, &times)) {

              fprintf(config->global->errors,

                      "Failed to set filetime %ld on outfile: errno %d\n",

                      filetime, errno);

            }

#endif

          }

        }

#endif /* defined(HAVE_UTIME) || \

          (defined(WIN32) && (CURL_SIZEOF_CURL_OFF_T >= 8)) */



#ifdef USE_METALINK

        if(!metalink && config->use_metalink && result == CURLE_OK) {