[FIX] BMP for MUC nicks, dip toes in vCard avatars

Can, your, Bifrost, Do, That. -lh

src/Unistr.c

@@ -0,0 +1,225 @@
+#include <Unistring.h>
+
+#include <Cytoplasm/Memory.h>
+#include <Cytoplasm/Str.h>
+#include <Cytoplasm/Log.h>
+
+#include <string.h>
+
+struct Unistr {
+    size_t length;
+    uint32_t *codepoints;
+};
+
+void 
+UnistrAddch(Unistr *unistr, uint32_t u)
+{
+    if (!unistr || !u)
+    {
+        return;
+    }
+    unistr->length++;
+    unistr->codepoints = Realloc(
+        unistr->codepoints, 
+        unistr->length * sizeof(*unistr->codepoints)
+    );
+
+    unistr->codepoints[unistr->length - 1] = u;
+}
+
+static bool
+UTFIsN(char *off, size_t available, int n, uint8_t pc)
+{
+    int i;
+    uint8_t *offu = (uint8_t *) off;
+    if ((available < n) || ((*offu >> (8-n-1)) != pc))
+    {
+        return false;
+    }
+
+    for (i = 0; i < n - 1; i++)
+    {
+        if ((offu[i+1] >> 6) != 0b10)
+        {
+            return false;
+        }
+    }
+    return true;
+}
+
+Unistr *
+UnistrCreate(char *src)
+{
+    size_t len, i;
+    Unistr *str;
+    char *start;
+    if (!src)
+    {
+        return NULL;
+    }
+
+    len = strlen(src);
+    str = Malloc(sizeof(*str));
+    str->length = 0;
+    str->codepoints = NULL;
+
+    /* We can't just set the length to {len}. */
+    for (i = 0; i < len; i++)
+    {
+        char byte = src[i];
+        size_t available = len - i;
+        if ((byte & 0x80) == 0)
+        {
+            /* This is a regular codepoint */
+            UnistrAddch(str, byte & 0x7F);
+            continue;
+        }
+        else if (UTFIsN(&src[i], available, 2, 0b110))
+        {
+            char a = src[i+0] & 0b00011111;
+            char b = src[i+1] & 0b00111111;
+            uint32_t u = (a << (6 * 1)) | b;
+
+            /* Overlongs are errors. */
+            if (u < 0x0080 || u > 0x07FF)
+            {
+                UnistrFree(str);
+                return NULL;
+            }
+
+            UnistrAddch(str, u);
+            i += 2 - 1;
+            continue;
+        }
+        else if (UTFIsN(&src[i], available, 3, 0b1110))
+        {
+            char a = src[i+0] & 0b00001111;
+            char b = src[i+1] & 0b00111111;
+            char c = src[i+2] & 0b00111111;
+            uint32_t u = 
+                (a << (6 * 2)) | 
+                (b << (6 * 1)) | 
+                (c << (6 * 0)) ;
+
+            /* Overlongs are errors. */
+            if (u < 0x0800 || u > 0xFFFF)
+            {
+                UnistrFree(str);
+                return NULL;
+            }
+
+            UnistrAddch(str, u);
+            i += 3 - 1;
+            continue;
+        }
+        else if (UTFIsN(&src[i], available, 4, 0b11110))
+        {
+            char a = src[i+0] & 0b00000111;
+            char b = src[i+1] & 0b00111111;
+            char c = src[i+2] & 0b00111111;
+            char d = src[i+3] & 0b00111111;
+            uint32_t u = 
+                (a << (6 * 3)) | 
+                (b << (6 * 2)) | 
+                (c << (6 * 1)) |
+                (d << (6 * 0)) ;
+
+            /* Overlongs are errors. */
+            if (u < 0x10000 || u > 0x10FFFF)
+            {
+                UnistrFree(str);
+                return NULL;
+            }
+
+            UnistrAddch(str, u);
+            i += 4 - 1;
+            continue;
+            
+        }
+    }
+
+    return str;
+}
+void 
+UnistrFree(Unistr *unistr)
+{
+    if (!unistr)
+    {
+        return;
+    }
+
+    Free(unistr->codepoints);
+    Free(unistr);
+}
+char * 
+UnistrC(Unistr *unistr)
+{
+    char *ret, *tmp, *utf;
+    size_t i;
+    if (!unistr)
+    {
+        return NULL;
+    }
+
+    ret = NULL;
+    for (i = 0; i < unistr->length; i++)
+    {
+        uint32_t code = unistr->codepoints[i];
+        utf = StrUtf8Encode(code);
+
+        tmp = ret;
+        ret = StrConcat(2, ret, utf);
+        Free(tmp);
+        Free(utf);
+    }
+
+    return ret;
+}
+size_t
+UnistrSize(Unistr *unistr)
+{
+    return unistr ? unistr->length : 0;
+}
+uint32_t 
+UnistrGetch(Unistr *unistr, size_t i)
+{
+    if (!unistr)
+    {
+        return 0;
+    }
+
+    return i < unistr->length ? unistr->codepoints[i] : 0;
+}
+bool
+UnistrIsBMP(uint32_t u)
+{
+    if (u == 0)
+    {
+        return NULL;
+    }
+
+    return u <= 0xFFFF;
+}
+Unistr *
+UnistrFilter(Unistr *str, UnistrFilterFunc filter)
+{
+    Unistr *unistr;
+    size_t i;
+    if (!str || !filter)
+    {
+        return NULL;
+    }
+
+    unistr = UnistrCreate("");
+    for (i = 0; i < UnistrSize(str); i++)
+    {
+        uint32_t code = UnistrGetch(str, i);
+        if (!filter(code))
+        {
+            continue;
+        }
+        UnistrAddch(unistr, code);
+    }
+
+    return unistr;
+}