Slightly more paranoia and slightly better comments for use of

Windows-specific MultiByteToWideChar/WideCharToMultiByte calls.

diff --git a/src/backend/utils/adt/oracle_compat.c b/src/backend/utils/adt/oracle_compat.c
index 4bf1e54466aaeb4ee70417d75674601ed8effef6..d580b2ec8edfb5656d1697e0297e9cab121f53a1 100644 (file)
--- a/src/backend/utils/adt/oracle_compat.c
+++ b/src/backend/utils/adt/oracle_compat.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/oracle_compat.c,v 1.74 2007/11/15 21:14:39 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/oracle_compat.c,v 1.75 2007/11/24 21:16:55 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -187,7 +187,7 @@ win32_utf8_texttowcs(const text *txt)
        r = MultiByteToWideChar(CP_UTF8, 0, VARDATA_ANY(txt), nbytes,
                                result, nbytes);
 
-       if (!r)                 /* assume it's NO_UNICODE_TRANSLATION */
+       if (r <= 0)             /* assume it's NO_UNICODE_TRANSLATION */
        {
            /* see notes above about error reporting */
            pg_verifymbstr(VARDATA_ANY(txt), nbytes, false);
@@ -198,6 +198,7 @@ win32_utf8_texttowcs(const text *txt)
        }
    }
 
+   /* Append trailing null wchar (MultiByteToWideChar won't have) */
    Assert(r <= nbytes);
    result[r] = 0;
 
@@ -212,8 +213,9 @@ win32_utf8_wcstotext(const wchar_t *str)
    int         nbytes;
    int         r;
 
+   /* Compute size of output string (this *will* include trailing null) */
    nbytes = WideCharToMultiByte(CP_UTF8, 0, str, -1, NULL, 0, NULL, NULL);
-   if (nbytes == 0)            /* shouldn't happen */
+   if (nbytes <= 0)            /* shouldn't happen */
        ereport(ERROR,
                (errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
                 errmsg("UTF-16 to UTF-8 translation failed: %lu",
@@ -223,7 +225,7 @@ win32_utf8_wcstotext(const wchar_t *str)
 
    r = WideCharToMultiByte(CP_UTF8, 0, str, -1, VARDATA(result), nbytes,
                            NULL, NULL);
-   if (r == 0)                 /* shouldn't happen */
+   if (r != nbytes)            /* shouldn't happen */
        ereport(ERROR,
                (errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
                 errmsg("UTF-16 to UTF-8 translation failed: %lu",