[v3 PATCH 03/13] expand: Count multi-byte characters for VSLENGTH

Herbert Xu
2024-05-05T09:14:34Z

Count multi-byte characters in variables and rather than bytes
and return that as the length expansion.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
src/expand.c | 62 +++++++++++++++++++++++++++++++++++++---------------
1 file changed, 44 insertions(+), 18 deletions(-)

diff --git a/src/expand.c b/src/expand.c
index 9ac981e..ad186b0 100644
--- a/src/expand.c
+++ b/src/expand.c
@@ -53,6 +53,7 @@
#endif
#include <ctype.h>
#include <stdbool.h>
+#include <wchar.h>

/*
* Routines to expand arguments to commands. We have to deal with
@@ -796,6 +797,18 @@ really_record:
return p;
}

+static char *chtodest(int c, int flags, char *out)
+{
+ const char *syntax = flags & EXP_QUOTED ? DQSYNTAX : BASESYNTAX;
+
+ if ((flags & QUOTES_ESC) &&
+ ((syntax[c] == CCTL) ||
+ (flags & EXP_QUOTED && syntax[c] == CBACK)))
+ USTPUTC(CTLESC, out);
+ USTPUTC(c, out);
+
+ return out;
+}

/*
* Put a string on the stack.
@@ -803,38 +816,48 @@ really_record:

static size_t memtodest(const char *p, size_t len, int flags)
{
- const char *syntax = flags & EXP_QUOTED ? DQSYNTAX : BASESYNTAX;
+ size_t count = 0;
char *q;
- char *s;
+ int c;

if (unlikely(!len))
return 0;

q = makestrspace(len * 2, expdest);
- s = q;

do {
- int c = (signed char)*p++;
- if (c) {
- if ((flags & QUOTES_ESC) &&
- ((syntax[c] == CCTL) ||
- (flags & EXP_QUOTED && syntax[c] == CBACK)))
- USTPUTC(CTLESC, q);
- } else if (!(flags & EXP_KEEPNUL))
+ c = (signed char)*p++;
+
+ if (c)
+ count++;
+ else if (!(flags & EXP_KEEPNUL))
continue;
- USTPUTC(c, q);
+
+ if (c < 0) {
+ mbstate_t mbs = {};
+
+ p--;
+ do {
+ q = chtodest(c, flags, q);
+ } while (mbrlen(p++, 1, &mbs) == -2 &&
+ (c = *p, --len));
+ if (!len)
+ break;
+ continue;
+ }
+
+ q = chtodest(c, flags, q);
} while (--len);

expdest = q;
- return q - s;
+ return count;
}

static size_t strtodest(const char *p, int flags)
{
size_t len = strlen(p);
- memtodest(p, len, flags);
- return len;
+ return memtodest(p, len, flags);
}

@@ -856,6 +879,7 @@ varvalue(char *name, int varflags, int flags, int quoted)
int discard = (subtype == VSPLUS || subtype == VSLENGTH) |
(flags & EXP_DISCARD);
ssize_t len = 0;
+ size_t start;
char c;

if (!subtype) {
@@ -865,9 +889,9 @@ varvalue(char *name, int varflags, int flags, int quoted)
sh_error("Bad substitution");
}

- flags |= EXP_KEEPNUL;
flags &= discard ? ~QUOTES_ESC : ~0;
sep = (flags & EXP_FULL) << CHAR_BIT;
+ start = expdest - (char *)stackblock();

switch (*name) {
case '$':
@@ -927,7 +951,7 @@ param:

if (*ap && sep) {
len++;
- memtodest(&sepc, 1, flags);
+ memtodest(&sepc, 1, flags | EXP_KEEPNUL);
}
}
break;
@@ -957,7 +981,7 @@ value:
}

if (discard)
- STADJUST(-len, expdest);
+ expdest = (char *)stackblock() + start;

return len;
}
@@ -1758,11 +1782,13 @@ casematch(union node *pattern, char *val)

static size_t cvtnum(intmax_t num, int flags)
{
+ size_t start = expdest - (char *)stackblock();
int len = max_int_length(sizeof(num));
char buf[len];

len = fmtstr(buf, len, "%" PRIdMAX, num);
- return memtodest(buf, len, flags);
+ memtodest(buf, len, flags);
+ return (expdest - (char *)stackblock()) - start;
}

STATIC void
--
2.39.2