thodg/libgit2/src/win32/utf-conv.c

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• Hash : 3603cb09
  Author :
  Date : 2015-02-10T23:13:49
  

  git__*allocarray: safer realloc and malloc Introduce git__reallocarray that checks the product of the number of elements and element size for overflow before allocation. Also introduce git__mallocarray that behaves like calloc, but without the `c`. (It does not zero memory, for those truly worried about every cycle.)

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• src/win32/utf-conv.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #include "common.h"
  #include "utf-conv.h"
  
  #ifndef WC_ERR_INVALID_CHARS
  # define WC_ERR_INVALID_CHARS	0x80
  #endif
  
  GIT_INLINE(DWORD) get_wc_flags(void)
  {
  	static char inited = 0;
  	static DWORD flags;
  
  	/* Invalid code point check supported on Vista+ only */
  	if (!inited) {
  		flags = git_has_win32_version(6, 0, 0) ? WC_ERR_INVALID_CHARS : 0;
  		inited = 1;
  	}
  
  	return flags;
  }
  
  GIT_INLINE(void) git__set_errno(void)
  {
  	if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
  		errno = ENAMETOOLONG;
  	else
  		errno = EINVAL;
  }
  
  /**
   * Converts a UTF-8 string to wide characters.
   *
   * @param dest The buffer to receive the wide string.
   * @param dest_size The size of the buffer, in characters.
   * @param src The UTF-8 string to convert.
   * @return The length of the wide string, in characters (not counting the NULL terminator), or < 0 for failure
   */
  int git__utf8_to_16(wchar_t *dest, size_t dest_size, const char *src)
  {
  	int len;
  
  	/* Length of -1 indicates NULL termination of the input string. Subtract 1 from the result to
  	* turn 0 into -1 (an error code) and to not count the NULL terminator as part of the string's
  	* length. MultiByteToWideChar never returns int's minvalue, so underflow is not possible */
  	if ((len = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, src, -1, dest, (int)dest_size) - 1) < 0)
  		git__set_errno();
  
  	return len;
  }
  
  /**
   * Converts a wide string to UTF-8.
   *
   * @param dest The buffer to receive the UTF-8 string.
   * @param dest_size The size of the buffer, in bytes.
   * @param src The wide string to convert.
   * @return The length of the UTF-8 string, in bytes (not counting the NULL terminator), or < 0 for failure
   */
  int git__utf16_to_8(char *dest, size_t dest_size, const wchar_t *src)
  {
  	int len;
  
  	/* Length of -1 indicates NULL termination of the input string. Subtract 1 from the result to
  	 * turn 0 into -1 (an error code) and to not count the NULL terminator as part of the string's
  	 * length. WideCharToMultiByte never returns int's minvalue, so underflow is not possible */
  	if ((len = WideCharToMultiByte(CP_UTF8, get_wc_flags(), src, -1, dest, (int)dest_size, NULL, NULL) - 1) < 0)
  		git__set_errno();
  
  	return len;
  }
  
  /**
   * Converts a UTF-8 string to wide characters.
   * Memory is allocated to hold the converted string.
   * The caller is responsible for freeing the string with git__free.
   *
   * @param dest Receives a pointer to the wide string.
   * @param src The UTF-8 string to convert.
   * @return The length of the wide string, in characters (not counting the NULL terminator), or < 0 for failure
   */
  int git__utf8_to_16_alloc(wchar_t **dest, const char *src)
  {
  	int utf16_size;
  
  	*dest = NULL;
  
  	/* Length of -1 indicates NULL termination of the input string */
  	utf16_size = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, src, -1, NULL, 0);
  
  	if (!utf16_size) {
  		git__set_errno();
  		return -1;
  	}
  
  	if (!(*dest = git__mallocarray(utf16_size, sizeof(wchar_t)))) {
  		errno = ENOMEM;
  		return -1;
  	}
  
  	utf16_size = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, src, -1, *dest, utf16_size);
  
  	if (!utf16_size) {
  		git__set_errno();
  
  		git__free(*dest);
  		*dest = NULL;
  	}
  
  	/* Subtract 1 from the result to turn 0 into -1 (an error code) and to not count the NULL
  	 * terminator as part of the string's length. MultiByteToWideChar never returns int's minvalue,
  	 * so underflow is not possible */
  	return utf16_size - 1;
  }
  
  /**
   * Converts a wide string to UTF-8.
   * Memory is allocated to hold the converted string.
   * The caller is responsible for freeing the string with git__free.
   *
   * @param dest Receives a pointer to the UTF-8 string.
   * @param src The wide string to convert.
   * @return The length of the UTF-8 string, in bytes (not counting the NULL terminator), or < 0 for failure
   */
  int git__utf16_to_8_alloc(char **dest, const wchar_t *src)
  {
  	int utf8_size;
  	DWORD dwFlags = get_wc_flags();
  
  	*dest = NULL;
  
  	/* Length of -1 indicates NULL termination of the input string */
  	utf8_size = WideCharToMultiByte(CP_UTF8, dwFlags, src, -1, NULL, 0, NULL, NULL);
  
  	if (!utf8_size) {
  		git__set_errno();
  		return -1;
  	}
  
  	*dest = git__malloc(utf8_size);
  
  	if (!*dest) {
  		errno = ENOMEM;
  		return -1;
  	}
  
  	utf8_size = WideCharToMultiByte(CP_UTF8, dwFlags, src, -1, *dest, utf8_size, NULL, NULL);
  
  	if (!utf8_size) {
  		git__set_errno();
  
  		git__free(*dest);
  		*dest = NULL;
  	}
  
  	/* Subtract 1 from the result to turn 0 into -1 (an error code) and to not count the NULL
  	 * terminator as part of the string's length. MultiByteToWideChar never returns int's minvalue,
  	 * so underflow is not possible */
  	return utf8_size - 1;
  }
  

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