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  1. Core ReactOS
  2. CORE-19396

Visual C++ 6.0 does not start (MSDEV loops at 100% CPU forever)

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Details

    • Bug
    • Resolution: Fixed
    • Major
    • 0.4.16
    • CRT
    • None

    Description

      reactos-bootcd-0.4.15-dev-7320-gf2d34ab-x86-gcc-lin-dbg

      Note : installation needs WineVDM and https://github.com/reactos/reactos/pull/6184 to be applied

      • Start Microsoft Visual C++ 6.0
      • MSDEV.EXE stuck at 100% cpu forever

      According to simonelombardo investigation shared in Mattermost chat, this comes from a recurring iteration on _ismbcspace which is not implemented correctly

      https://github.com/reactos/reactos/blob/master/sdk/lib/crt/mbstring/ismbc.c#L69

      /*
       * @implemented
       */
      int _ismbcspace( unsigned int c )
      {
          return ((c) == 0x8140);
      } 

      while its specification is

      https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/ismbcgraph-functions?view=msvc-170

      _ismbcspace | White space | Returns nonzero if and only if c is a white-space character: c=0x20 or 0x09<=c<=0x0D. 

      Attachments

        1. _ismbcspace.c
          0.9 kB
          DougLyons
        2. image.png
          253 kB
          simonelombardo
        3. image-2023-12-23-15-18-59-497.png
          60 kB
          KRosUser
        4. image-2025-05-04-19-06-04-293.png
          61 kB
          KRosUser
        5. MSVC++_6.0-fixed.png
          161 kB
          DougLyons
        6. MSVC++_6.0-ismbcspace-02.patch
          5 kB
          DougLyons
        7. MSVC++_6.0-ismbcspace-03.patch
          0.4 kB
          DougLyons
        8. ReactOS.log
          219 kB
          KRosUser

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              DougLyons DougLyons
              KRosUser KRosUser
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              Dates

                Created:
                Updated:
                Resolved: