From 0281ee40d079fb3206a6c9ae9ed52566f64e9803 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= Date: Tue, 12 Jan 2016 15:36:57 -0500 Subject: [PATCH] basic/escape: merge utf8 and non-utf8 paths in cunescape_one Not every byte sequence is valid utf8. We allow escaping of non-utf8 sequences in strings by using octal and hexadecimal escape sequences (\123 and \0xAB) for bytes at or above 128. Users of cunescape_one could infer whether such use occured when they received an answer between 128 and 256 in *ret (a non-ascii one byte character). But this is subtle and misleading: the comments were wrong, because ascii is a subset of unicode, so c != 0 did not mean non-unicode, but rather ascii-subset-of-unicode-or-raw-byte. This was all rather confusing, so make the "single byte" condition explicit. I'm not convinced that allowing non-utf8 sequences to be produced is useful in all cases where we allow it (e.g. in config files), but that behaviour is unchanged, just made more explicit. This also fixes an (invalid) gcc warning about unitialized variable (*ret_unicode) in callers of cunescape_one. --- src/basic/escape.c | 51 ++++++++++++++-------------------------- src/basic/escape.h | 2 +- src/basic/extract-word.c | 9 +++---- 3 files changed, 24 insertions(+), 38 deletions(-) diff --git a/src/basic/escape.c b/src/basic/escape.c index 42a84c931..9dbfa6d6e 100644 --- a/src/basic/escape.c +++ b/src/basic/escape.c @@ -116,16 +116,18 @@ char *cescape(const char *s) { return cescape_length(s, strlen(s)); } -int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode) { +int cunescape_one(const char *p, size_t length, uint32_t *ret, bool *eight_bit) { int r = 1; assert(p); assert(*p); assert(ret); - /* Unescapes C style. Returns the unescaped character in ret, - * unless we encountered a \u sequence in which case the full - * unicode character is returned in ret_unicode, instead. */ + /* Unescapes C style. Returns the unescaped character in ret. + * Sets *eight_bit to true if the escaped sequence either fits in + * one byte in UTF-8 or is a non-unicode literal byte and should + * instead be copied directly. + */ if (length != (size_t) -1 && length < 1) return -EINVAL; @@ -187,7 +189,8 @@ int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode if (a == 0 && b == 0) return -EINVAL; - *ret = (char) ((a << 4U) | b); + *ret = (a << 4U) | b; + *eight_bit = true; r = 3; break; } @@ -214,16 +217,7 @@ int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode if (c == 0) return -EINVAL; - if (c < 128) - *ret = c; - else { - if (!ret_unicode) - return -EINVAL; - - *ret = 0; - *ret_unicode = c; - } - + *ret = c; r = 5; break; } @@ -255,16 +249,7 @@ int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode if (!unichar_is_valid(c)) return -EINVAL; - if (c < 128) - *ret = c; - else { - if (!ret_unicode) - return -EINVAL; - - *ret = 0; - *ret_unicode = c; - } - + *ret = c; r = 9; break; } @@ -306,6 +291,7 @@ int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode return -EINVAL; *ret = m; + *eight_bit = true; r = 3; break; } @@ -339,7 +325,7 @@ int cunescape_length_with_prefix(const char *s, size_t length, const char *prefi for (f = s, t = r + pl; f < s + length; f++) { size_t remaining; uint32_t u; - char c; + bool eight_bit = false; int k; remaining = s + length - f; @@ -362,7 +348,7 @@ int cunescape_length_with_prefix(const char *s, size_t length, const char *prefi return -EINVAL; } - k = cunescape_one(f + 1, remaining - 1, &c, &u); + k = cunescape_one(f + 1, remaining - 1, &u, &eight_bit); if (k < 0) { if (flags & UNESCAPE_RELAX) { /* Invalid escape code, let's take it literal then */ @@ -374,14 +360,13 @@ int cunescape_length_with_prefix(const char *s, size_t length, const char *prefi return k; } - if (c != 0) - /* Non-Unicode? Let's encode this directly */ - *(t++) = c; + f += k; + if (eight_bit) + /* One byte? Set directly as specified */ + *(t++) = u; else - /* Unicode? Then let's encode this in UTF-8 */ + /* Otherwise encode as multi-byte UTF-8 */ t += utf8_encode_unichar(t, u); - - f += k; } *t = 0; diff --git a/src/basic/escape.h b/src/basic/escape.h index 84916387a..6777de692 100644 --- a/src/basic/escape.h +++ b/src/basic/escape.h @@ -41,7 +41,7 @@ size_t cescape_char(char c, char *buf); int cunescape(const char *s, UnescapeFlags flags, char **ret); int cunescape_length(const char *s, size_t length, UnescapeFlags flags, char **ret); int cunescape_length_with_prefix(const char *s, size_t length, const char *prefix, UnescapeFlags flags, char **ret); -int cunescape_one(const char *p, size_t length, char *ret, uint32_t *ret_unicode); +int cunescape_one(const char *p, size_t length, uint32_t *ret, bool *eight_bit); char *xescape(const char *s, const char *bad); diff --git a/src/basic/extract-word.c b/src/basic/extract-word.c index 5b993e870..de5616890 100644 --- a/src/basic/extract-word.c +++ b/src/basic/extract-word.c @@ -98,8 +98,9 @@ int extract_first_word(const char **p, char **ret, const char *separators, Extra if (flags & EXTRACT_CUNESCAPE) { uint32_t u; + bool eight_bit = false; - r = cunescape_one(*p, (size_t) -1, &c, &u); + r = cunescape_one(*p, (size_t) -1, &u, &eight_bit); if (r < 0) { if (flags & EXTRACT_CUNESCAPE_RELAX) { s[sz++] = '\\'; @@ -109,10 +110,10 @@ int extract_first_word(const char **p, char **ret, const char *separators, Extra } else { (*p) += r - 1; - if (c != 0) - s[sz++] = c; /* normal explicit char */ + if (eight_bit) + s[sz++] = u; else - sz += utf8_encode_unichar(s + sz, u); /* unicode chars we'll encode as utf8 */ + sz += utf8_encode_unichar(s + sz, u); } } else s[sz++] = c; -- 2.30.2