From 471149c262613e4b69fc14b9599fe541106084e4 Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Wed, 10 May 2017 06:41:50 -0700
Subject: ffi: adjust semantics of zarray of characters.

We want to be able to extract null-terminated UTF-8 strings
from arrays, without trailing junk, yet retain the ability to
extract the entire array including embedded nulls. The natural
way is to use the array/zarray distinction.

* ffi.c (ffi_array_in, ffi_array_get): Don't try to guess
whether the array is null terminated; just rely on the
null_term flag, and treat accordingly.

* txr.1: Doc updated.
---
 ffi.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

(limited to 'ffi.c')

diff --git a/ffi.c b/ffi.c
index 5918933d..8c99f3d9 100644
--- a/ffi.c
+++ b/ffi.c
@@ -1008,7 +1008,7 @@ static val ffi_array_in(struct txr_ffi_type *tft, int copy, mem_t *src,
       str = null_string;
     } else {
       const char *chptr = coerce(const char *, src);
-      if (chptr[tft->size - 1] == 0) {
+      if (tft->null_term) {
         str = string_utf8(chptr);
       } else {
         wchar_t *wch = utf8_dup_from_buf(chptr, tft->size);
@@ -1022,13 +1022,12 @@ static val ffi_array_in(struct txr_ffi_type *tft, int copy, mem_t *src,
     if (nelem == 0) {
       str = null_string;
     } else {
-      cnum nchar = tft->size / sizeof (wchar_t);
       const wchar_t *wchptr = coerce(const wchar_t *, src);
 
-      if (wchptr[nchar - 1] == 0) {
+      if (tft->null_term) {
         str = string(wchptr);
       } else {
-        val ustr = mkustring(num_fast(nchar));
+        val ustr = mkustring(num_fast(nelem));
         str = init_str(ustr, wchptr);
       }
     }
@@ -1040,7 +1039,7 @@ static val ffi_array_in(struct txr_ffi_type *tft, int copy, mem_t *src,
       str = null_string;
     } else {
       const unsigned char *chptr = coerce(const unsigned char *, src);
-      if (chptr[tft->size - 1] == 0)
+      if (tft->null_term)
         str = string_8bit(chptr);
       else
         str = string_8bit_size(chptr, tft->size);
@@ -1129,7 +1128,7 @@ static val ffi_array_get(struct txr_ffi_type *tft, mem_t *src, val self)
       return null_string;
     } else {
       const char *chptr = coerce(const char *, src);
-      if (chptr[tft->size - 1] == 0) {
+      if (tft->null_term) {
         return string_utf8(chptr);
       } else {
         wchar_t *wch = utf8_dup_from_buf(chptr, tft->size);
@@ -1140,13 +1139,12 @@ static val ffi_array_get(struct txr_ffi_type *tft, mem_t *src, val self)
     if (nelem == 0) {
       return null_string;
     } else {
-      cnum nchar = tft->size / sizeof (wchar_t);
       const wchar_t *wchptr = coerce(const wchar_t *, src);
 
-      if (wchptr[nchar - 1] == 0) {
+      if (tft->null_term) {
         return string(wchptr);
       } else {
-        val ustr = mkustring(num_fast(nchar));
+        val ustr = mkustring(num_fast(nelem));
         return init_str(ustr, wchptr);
       }
     }
@@ -1155,7 +1153,7 @@ static val ffi_array_get(struct txr_ffi_type *tft, mem_t *src, val self)
       return null_string;
     } else {
       const unsigned char *chptr = coerce(const unsigned char *, src);
-      if (chptr[tft->size - 1] == 0)
+      if (tft->null_term)
         return string_8bit(chptr);
       else
         return string_8bit_size(chptr, tft->size);
-- 
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