diff options
Diffstat (limited to 'generic')
| -rw-r--r-- | generic/tclUtf.c | 96 |
1 files changed, 88 insertions, 8 deletions
diff --git a/generic/tclUtf.c b/generic/tclUtf.c index 89c6b60..a04dca8 100644 --- a/generic/tclUtf.c +++ b/generic/tclUtf.c @@ -8,7 +8,7 @@ * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclUtf.c,v 1.2 1999/04/16 00:46:55 stanton Exp $ + * RCS: @(#) $Id: tclUtf.c,v 1.3 1999/04/29 00:04:41 hershey Exp $ */ #include "tclInt.h" @@ -73,6 +73,12 @@ CONST unsigned char totalBytes[256] = { #endif }; +/* + * Procedures used only in this module. + */ + +static int UtfCount _ANSI_ARGS_((int ch)); + /* *--------------------------------------------------------------------------- @@ -80,6 +86,50 @@ CONST unsigned char totalBytes[256] = { * Tcl_UniCharToUtf -- * * Store the given Tcl_UniChar as a sequence of UTF-8 bytes in the + * Utf character "ch". + * + * Results: + * The return values is the number of bytes in the Utf character "ch". + * + * Side effects: + * None. + * + *--------------------------------------------------------------------------- + */ + +static int +UtfCount(ch) + int ch; /* The Tcl_UniChar whose size is returned. */ +{ + if ((ch > 0) && (ch < UNICODE_SELF)) { + return 1; + } + if (ch <= 0x7FF) { + return 2; + } + if (ch <= 0xFFFF) { + return 3; + } +#if TCL_UTF_MAX > 3 + if (ch <= 0x1FFFFF) { + return 4; + } + if (ch <= 0x3FFFFFF) { + return 5; + } + if (ch <= 0x7FFFFFFF) { + return 6; + } +#endif + return 3; +} + +/* + *--------------------------------------------------------------------------- + * + * Tcl_UniCharToUtf -- + * + * Store the given Tcl_UniChar as a sequence of UTF-8 bytes in the * provided buffer. Equivalent to Plan 9 runetochar(). * * Results: @@ -849,17 +899,32 @@ int Tcl_UtfToUpper(str) char *str; /* String to convert in place. */ { - Tcl_UniChar ch; + Tcl_UniChar ch, upChar; char *src, *dst; - + int bytes; + /* * Iterate over the string until we hit the terminating null. */ src = dst = str; while (*src) { - src += Tcl_UtfToUniChar(src, &ch); - dst += Tcl_UniCharToUtf(Tcl_UniCharToUpper(ch), dst); + bytes = Tcl_UtfToUniChar(src, &ch); + upChar = Tcl_UniCharToUpper(ch); + + /* + * To keep badly formed Utf strings from getting inflated by + * the conversion (thereby causing a segfault), only copy the + * upper case char to dst if its size is <= the original char. + */ + + if (bytes < UtfCount(upChar)) { + memcpy(dst, src, (size_t) bytes); + dst += bytes; + } else { + dst += Tcl_UniCharToUtf(upChar, dst); + } + src += bytes; } *dst = '\0'; return (dst - str); @@ -887,8 +952,9 @@ int Tcl_UtfToLower(str) char *str; /* String to convert in place. */ { - Tcl_UniChar ch; + Tcl_UniChar ch, lowChar; char *src, *dst; + int bytes; /* * Iterate over the string until we hit the terminating null. @@ -896,8 +962,22 @@ Tcl_UtfToLower(str) src = dst = str; while (*src) { - src += Tcl_UtfToUniChar(src, &ch); - dst += Tcl_UniCharToUtf(Tcl_UniCharToLower(ch), dst); + bytes = Tcl_UtfToUniChar(src, &ch); + lowChar = Tcl_UniCharToLower(ch); + + /* + * To keep badly formed Utf strings from getting inflated by + * the conversion (thereby causing a segfault), only copy the + * lower case char to dst if its size is <= the original char. + */ + + if (bytes < UtfCount(lowChar)) { + memcpy(dst, src, (size_t) bytes); + dst += bytes; + } else { + dst += Tcl_UniCharToUtf(lowChar, dst); + } + src += bytes; } *dst = '\0'; return (dst - str); |