X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futf8.c;h=800884ffee99c77b36c6c16f35015a70442409fa;hp=03a0abe44b7df0bd05d676476cf38db5412ba800;hb=b733fbe7a0214eb43e402db7179697bf9c0975c1;hpb=b0ceb53a7ddb94269f70b2769bbc72870e574111

diff --git a/src/shared/utf8.c b/src/shared/utf8.c
index 03a0abe44..800884ffe 100644
--- a/src/shared/utf8.c
+++ b/src/shared/utf8.c
@@ -52,7 +52,7 @@
 #include "utf8.h"
 #include "util.h"
 
-static inline bool is_unicode_valid(uint32_t ch) {
+bool unichar_is_valid(uint32_t ch) {
 
         if (ch >= 0x110000) /* End of unicode space */
                 return false;
@@ -66,7 +66,7 @@ static inline bool is_unicode_valid(uint32_t ch) {
         return true;
 }
 
-static bool is_unicode_control(uint32_t ch) {
+static bool unichar_is_control(uint32_t ch) {
 
         /*
           0 to ' '-1 is the C0 range.
@@ -156,7 +156,7 @@ bool utf8_is_printable_newline(const char* str, size_t length, bool newline) {
 
                 val = utf8_encoded_to_unichar(p);
                 if (val < 0 ||
-                    is_unicode_control(val) ||
+                    unichar_is_control(val) ||
                     (!newline && val == '\n'))
                         return false;
 
@@ -263,34 +263,90 @@ char *ascii_is_valid(const char *str) {
         return (char*) str;
 }
 
-int utf8_encode_unichar(uint16_t c, char *p) {
-        uint8_t *t = (uint8_t*) p;
+/**
+ * utf8_encode_unichar() - Encode single UCS-4 character as UTF-8
+ * @out_utf8: output buffer of at least 4 bytes or NULL
+ * @g: UCS-4 character to encode
+ *
+ * This encodes a single UCS-4 character as UTF-8 and writes it into @out_utf8.
+ * The length of the character is returned. It is not zero-terminated! If the
+ * output buffer is NULL, only the length is returned.
+ *
+ * Returns: The length in bytes that the UTF-8 representation does or would
+ *          occupy.
+ */
+size_t utf8_encode_unichar(char *out_utf8, uint32_t g) {
 
-        if (c < 0x80) {
-                t[0] = (uint8_t) c;
+        if (g < (1 << 7)) {
+                if (out_utf8)
+                        out_utf8[0] = g & 0x7f;
                 return 1;
-        } else if (c < 0x800) {
-                t[0] = (uint8_t) (0xc0 | (c >> 6));
-                t[1] = (uint8_t) (0x80 | (c & 0x3f));
+        } else if (g < (1 << 11)) {
+                if (out_utf8) {
+                        out_utf8[0] = 0xc0 | ((g >> 6) & 0x1f);
+                        out_utf8[1] = 0x80 | (g & 0x3f);
+                }
                 return 2;
-        } else {
-                t[0] = (uint8_t) (0xe0 | (c >> 12));
-                t[1] = (uint8_t) (0x80 | ((c >> 6) & 0x3f));
-                t[2] = (uint8_t) (0x80 | (c & 0x3f));
+        } else if (g < (1 << 16)) {
+                if (out_utf8) {
+                        out_utf8[0] = 0xe0 | ((g >> 12) & 0x0f);
+                        out_utf8[1] = 0x80 | ((g >> 6) & 0x3f);
+                        out_utf8[2] = 0x80 | (g & 0x3f);
+                }
                 return 3;
+        } else if (g < (1 << 21)) {
+                if (out_utf8) {
+                        out_utf8[0] = 0xf0 | ((g >> 18) & 0x07);
+                        out_utf8[1] = 0x80 | ((g >> 12) & 0x3f);
+                        out_utf8[2] = 0x80 | ((g >> 6) & 0x3f);
+                        out_utf8[3] = 0x80 | (g & 0x3f);
+                }
+                return 4;
         }
+
+        return 0;
 }
 
 char *utf16_to_utf8(const void *s, size_t length) {
         const uint8_t *f;
         char *r, *t;
 
-        r = new(char, (length*3+1)/2 + 1);
+        r = new(char, (length * 4 + 1) / 2 + 1);
         if (!r)
                 return NULL;
 
-        for (f = s, t = r; f < (const uint8_t*) s + length; f += 2)
-                t += utf8_encode_unichar((f[1] << 8) | f[0], t);
+        f = s;
+        t = r;
+
+        while (f < (const uint8_t*) s + length) {
+                uint16_t w1, w2;
+
+                /* see RFC 2781 section 2.2 */
+
+                w1 = f[1] << 8 | f[0];
+                f += 2;
+
+                if (!utf16_is_surrogate(w1)) {
+                        t += utf8_encode_unichar(t, w1);
+
+                        continue;
+                }
+
+                if (utf16_is_trailing_surrogate(w1))
+                        continue;
+                else if (f >= (const uint8_t*) s + length)
+                        break;
+
+                w2 = f[1] << 8 | f[0];
+                f += 2;
+
+                if (!utf16_is_trailing_surrogate(w2)) {
+                        f -= 2;
+                        continue;
+                }
+
+                t += utf8_encode_unichar(t, utf16_surrogate_pair_to_unichar(w1, w2));
+        }
 
         *t = 0;
         return r;
@@ -339,7 +395,7 @@ int utf8_encoded_valid_unichar(const char *str) {
                 return -EINVAL;
 
         /* check if value has valid range */
-        if (!is_unicode_valid(unichar))
+        if (!unichar_is_valid(unichar))
                 return -EINVAL;
 
         return len;