Issue 686: Keep retrying until buffer is big enough

@duy-github pointed out that commit 9134c3a fixed
one place where this mistake occurred, but left three
other places.

1 files changed, 27 insertions, 24 deletions

diff --git a/libarchive/archive_string.c b/libarchive/archive_string.c
index 282c58e1..33094f47 100644
--- a/libarchive/archive_string.c
+++ b/libarchive/archive_string.c
@@ -559,7 +559,8 @@ archive_wstring_append_from_mbs_in_codepage(struct archive_wstring *dest,
 			}
 			if (count == 0 && length != 0)
 				ret = -1;
-		} while (0);
+			break;
+		} while (1);
 	}
 	dest->length += count;
 	dest->s[dest->length] = L'\0';
@@ -3552,18 +3553,19 @@ win_strncat_from_utf16(struct archive_string *as, const void *_p, size_t bytes,
 		ll = WideCharToMultiByte(sc->to_cp, 0,
 		    (LPCWSTR)u16, (int)bytes>>1, mbs, (int)mbs_size,
 			NULL, &defchar);
-		if (ll == 0 &&
-		    GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
-			/* Need more buffer for MBS. */
-			ll = WideCharToMultiByte(sc->to_cp, 0,
-			    (LPCWSTR)u16, (int)bytes, NULL, 0, NULL, NULL);
-			if (archive_string_ensure(as, ll +1) == NULL)
-				return (-1);
-			mbs = as->s + as->length;
-			mbs_size = as->buffer_length - as->length -1;
-			continue;
+		/* Exit loop if we succeeded */
+		if (ll != 0 ||
+		    GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
+			break;
 		}
-	} while (0);
+		/* Else expand buffer and loop to try again. */
+		ll = WideCharToMultiByte(sc->to_cp, 0,
+		    (LPCWSTR)u16, (int)bytes, NULL, 0, NULL, NULL);
+		if (archive_string_ensure(as, ll +1) == NULL)
+			return (-1);
+		mbs = as->s + as->length;
+		mbs_size = as->buffer_length - as->length -1;
+	} while (1);
 	archive_string_free(&tmp);
 	as->length += ll;
 	as->s[as->length] = '\0';
@@ -3634,19 +3636,20 @@ win_strncat_to_utf16(struct archive_string *as16, const void *_p,
 	do {
 		count = MultiByteToWideChar(sc->from_cp,
 		    MB_PRECOMPOSED, s, (int)length, (LPWSTR)u16, (int)avail>>1);
-		if (count == 0 &&
-		    GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
-			/* Need more buffer for UTF-16 string */
-			count = MultiByteToWideChar(sc->from_cp,
-			    MB_PRECOMPOSED, s, (int)length, NULL, 0);
-			if (archive_string_ensure(as16, (count +1) * 2)
-			    == NULL)
-				return (-1);
-			u16 = as16->s + as16->length;
-			avail = as16->buffer_length - 2;
-			continue;
+		/* Exit loop if we succeeded */
+		if (count != 0 ||
+		    GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
+			break;
 		}
-	} while (0);
+		/* Expand buffer and try again */
+		count = MultiByteToWideChar(sc->from_cp,
+		    MB_PRECOMPOSED, s, (int)length, NULL, 0);
+		if (archive_string_ensure(as16, (count +1) * 2)
+		    == NULL)
+			return (-1);
+		u16 = as16->s + as16->length;
+		avail = as16->buffer_length - 2;
+	} while (1);
 	as16->length += count * 2;
 	as16->s[as16->length] = 0;
 	as16->s[as16->length+1] = 0;