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#include "syshdrs.h"
#ifdef PRAGMA_HDRSTOP
# pragma hdrstop
#endif
const char *
DStrCat(DStr *const dst, const char *const src)
{
size_t srcLen, allocSize, newLen, curLen;
char *cp;
if (IS_DSTR_CORRUPT(dst))
return NULL;
srcLen = strlen(src) + 1 /* copy NUL byte also */;
curLen = dst->len;
newLen = srcLen + curLen;
if (newLen > 0x00FFFFFF)
return NULL;
if (dst->allocSize < newLen) {
/* Need to resize buffer before copying. */
allocSize = (newLen + 16) & 0xFFFFFFF0;
if (dst->s == NULL) {
cp = calloc(allocSize, (size_t) 1);
if (cp == NULL)
return NULL;
} else {
cp = realloc(dst->s, allocSize);
if (cp == NULL)
return NULL;
memset(cp + curLen, 0, allocSize - curLen);
}
dst->s = cp;
dst->allocSize = allocSize;
} else {
cp = dst->s;
}
memcpy(cp + curLen, src, --srcLen);
dst->len = newLen - 1;
cp[newLen - 1] = '\0';
return (cp);
} /* DStrCat */
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