18     if (codepoint > 0x10FFFFu) {  in is_valid_codepoint()
21     if ((codepoint >= 0xFDD0 && codepoint <= 0xFDEF)  in is_valid_codepoint()
22         || (codepoint & 0xFFFE) == 0xFFFE) {  in is_valid_codepoint()
25     if (codepoint >= 0xD800 && codepoint <= 0xDFFF) {  in is_valid_codepoint()
44  * If @s points to an impossible byte (0xFE or 0xFF) or a continuation
64     static int min_cp[5] = { 0x80, 0x800, 0x10000, 0x200000, 0x4000000 };  in mod_utf8_codepoint()
69     if (n == 0 || *s == 0) {  in mod_utf8_codepoint()
77     if (byte < 0x80) {  in mod_utf8_codepoint()
79     } else if (byte >= 0xFE) {  in mod_utf8_codepoint()
80         cp = -1;                /* impossible bytes 0xFE, 0xFF */  in mod_utf8_codepoint()
81     } else if ((byte & 0x40) == 0) {  in mod_utf8_codepoint()
85         len = 0;  in mod_utf8_codepoint()
86         for (mask = 0x80; byte & mask; mask >>= 1) {  in mod_utf8_codepoint()
92             byte = i < n ? *p : 0;  in mod_utf8_codepoint()
93             if ((byte & 0xC0) != 0x80) {  in mod_utf8_codepoint()
99             cp |= byte & 0x3F;  in mod_utf8_codepoint()
103         } else if (cp < min_cp[len - 2] && !(cp == 0 && len == 2)) {  in mod_utf8_codepoint()
132     if (codepoint > 0 && codepoint <= 0x7F) {  in mod_utf8_encode()
133         buf[0] = codepoint & 0x7F;  in mod_utf8_encode()
134         buf[1] = 0;  in mod_utf8_encode()
137     if (codepoint <= 0x7FF) {  in mod_utf8_encode()
138         buf[0] = 0xC0 | ((codepoint >> 6) & 0x1F);  in mod_utf8_encode()
139         buf[1] = 0x80 | (codepoint & 0x3F);  in mod_utf8_encode()
140         buf[2] = 0;  in mod_utf8_encode()
143     if (codepoint <= 0xFFFF) {  in mod_utf8_encode()
144         buf[0] = 0xE0 | ((codepoint >> 12) & 0x0F);  in mod_utf8_encode()
145         buf[1] = 0x80 | ((codepoint >> 6) & 0x3F);  in mod_utf8_encode()
146         buf[2] = 0x80 | (codepoint & 0x3F);  in mod_utf8_encode()
147         buf[3] = 0;  in mod_utf8_encode()
150     buf[0] = 0xF0 | ((codepoint >> 18) & 0x07);  in mod_utf8_encode()
151     buf[1] = 0x80 | ((codepoint >> 12) & 0x3F);  in mod_utf8_encode()
152     buf[2] = 0x80 | ((codepoint >> 6) & 0x3F);  in mod_utf8_encode()
153     buf[3] = 0x80 | (codepoint & 0x3F);  in mod_utf8_encode()
154     buf[4] = 0;  in mod_utf8_encode()