UTF8 conversion stuff.

This is for dealing with Unicode file names which cannot be handled with an idealized Unicode approach as was present before.
utf8proc was included to handle normalization because with externally provided filenames we have no control over enforcing our pld rules.

src/common/filesystem/source/unicode.cpp

@@ -0,0 +1,143 @@
+/*
+** unicode.cpp
+** handling for conversion / comparison of filenames
+**
+**---------------------------------------------------------------------------
+** Copyright 2019 Christoph Oelckers
+** All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions
+** are met:
+**
+** 1. Redistributions of source code must retain the above copyright
+**    notice, this list of conditions and the following disclaimer.
+** 2. Redistributions in binary form must reproduce the above copyright
+**    notice, this list of conditions and the following disclaimer in the
+**    documentation and/or other materials provided with the distribution.
+** 3. The name of the author may not be used to endorse or promote products
+**    derived from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**---------------------------------------------------------------------------
+**
+*/
+
+#include "unicode.h"
+#include "utf8proc.h"
+
+namespace FileSys {
+//==========================================================================
+//
+//
+//
+//==========================================================================
+
+static void utf8_encode(int32_t codepoint, std::vector<char>& buffer)
+{
+	if (codepoint < 0 || codepoint > 0x10FFFF || (codepoint >= 0xD800 && codepoint < 0xDFFF))
+	{
+		codepoint = 0xFFFD;
+	}
+	uint8_t buf[4];
+	auto size = utf8proc_encode_char(codepoint, buf);
+	for(int i = 0; i < size; i++)
+		buffer.push_back(buf[i]);
+}
+
+
+//==========================================================================
+//
+// convert UTF16 to UTF8 (needed for 7z)
+//
+//==========================================================================
+
+void utf16_to_utf8(const unsigned short* in, std::vector<char>& buffer)
+{
+	buffer.clear();
+	if (!*in) return;
+
+	while (int char1 = *in++)
+	{
+		if (char1 >= 0xD800 && char1 <= 0xDBFF)
+		{
+			int char2 = *in;
+
+			if (char2 >= 0xDC00 && char2 <= 0xDFFF)
+			{
+				in++;
+				char1 -= 0xD800;
+				char2 -= 0xDC00;
+				char1 <<= 10;
+				char1 += char2;
+				char1 += 0x010000;
+			}
+			else
+			{
+				// invalid code point - replace with placeholder
+				char1 = 0xFFFD;
+			}
+		}
+		else if (char1 >= 0xDC00 && char1 <= 0xDFFF)
+		{
+			// invalid code point - replace with placeholder
+			char1 = 0xFFFD;
+		}
+		utf8_encode(char1, buffer);
+	}
+	buffer.push_back(0);
+}
+
+//==========================================================================
+//
+// convert UTF16 to UTF8 (needed for Zip)
+//
+//==========================================================================
+
+void ibm437_to_utf8(const char* in, std::vector<char>& buffer)
+{
+	static const uint16_t ibm437map[] = {
+		0x00c7,	0x00fc,	0x00e9,	0x00e2,	0x00e4,	0x00e0,	0x00e5,	0x00e7,	0x00ea,	0x00eb,	0x00e8,	0x00ef,	0x00ee,	0x00ec,	0x00c4,	0x00c5,
+		0x00c9,	0x00e6,	0x00c6,	0x00f4,	0x00f6,	0x00f2,	0x00fb,	0x00f9,	0x00ff,	0x00d6,	0x00dc,	0x00a2,	0x00a3,	0x00a5,	0x20a7,	0x0192,
+		0x00e1,	0x00ed,	0x00f3,	0x00fa,	0x00f1,	0x00d1,	0x00aa,	0x00ba,	0x00bf,	0x2310,	0x00ac,	0x00bd,	0x00bc,	0x00a1,	0x00ab,	0x00bb,
+		0x2591,	0x2592,	0x2593,	0x2502,	0x2524,	0x2561,	0x2562,	0x2556,	0x2555,	0x2563,	0x2551,	0x2557,	0x255d,	0x255c,	0x255b,	0x2510,
+		0x2514,	0x2534,	0x252c,	0x251c,	0x2500,	0x253c,	0x255e,	0x255f,	0x255a,	0x2554,	0x2569,	0x2566,	0x2560,	0x2550,	0x256c,	0x2567,
+		0x2568,	0x2564,	0x2565,	0x2559,	0x2558,	0x2552,	0x2553,	0x256b,	0x256a,	0x2518,	0x250c,	0x2588,	0x2584,	0x258c,	0x2590,	0x2580,
+		0x03b1,	0x00df,	0x0393,	0x03c0,	0x03a3,	0x03c3,	0x00b5,	0x03c4,	0x03a6,	0x0398,	0x03a9,	0x03b4,	0x221e,	0x03c6,	0x03b5,	0x2229,
+		0x2261,	0x00b1,	0x2265,	0x2264,	0x2320,	0x2321,	0x00f7,	0x2248,	0x00b0,	0x2219,	0x00b7,	0x221a,	0x207f,	0x00b2,	0x25a0,	0x00a0,
+	};
+	
+	buffer.clear();
+	if (!*in) return;
+
+	while (int char1 = (uint8_t)*in++)
+	{
+		if (char1 >= 0x80) char1 = ibm437map[char1];
+		utf8_encode(char1, buffer);
+	}
+	buffer.push_back(0);
+}
+
+//==========================================================================
+//
+// create a normalized lowercase version of a string.
+//
+//==========================================================================
+
+char *tolower_normalize(const char *str) 
+{
+	utf8proc_uint8_t *retval;
+	utf8proc_map((const uint8_t*)str, 0, &retval, (utf8proc_option_t)(UTF8PROC_NULLTERM | UTF8PROC_STABLE | UTF8PROC_COMPOSE | UTF8PROC_CASEFOLD));
+	return (char*)retval;
+}
+
+}