Simplify calling convention of u*_conv_to_encoding.

6 files changed, 117 insertions, 83 deletions

diff --git a/lib/unicase/u-casexfrm.h b/lib/unicase/u-casexfrm.h
index a7298a9701..e36aff3b9e 100644
--- a/lib/unicase/u-casexfrm.h
+++ b/lib/unicase/u-casexfrm.h
@@ -26,7 +26,6 @@ FUNC (const UNIT *s, size_t n, const char *iso639_language, uninorm_t nf,
   char convsbuf[2048];
   char *convs;
   size_t convs_length;
-  int ret;
   char *result;
 
   /* Casefold and normalize the Unicode string.  */
@@ -37,14 +36,13 @@ FUNC (const UNIT *s, size_t n, const char *iso639_language, uninorm_t nf,
     return NULL;
 
   /* Convert it to locale encoding.  */
-  convs = convsbuf;
   convs_length = sizeof (convsbuf) - 1;
-  ret = U_CONV_TO_ENCODING (locale_charset (),
-			    iconveh_error,
-			    foldeds, foldeds_length,
-			    NULL,
-			    &convs, &convs_length);
-  if (ret < 0)
+  convs = U_CONV_TO_ENCODING (locale_charset (),
+			      iconveh_error,
+			      foldeds, foldeds_length,
+			      NULL,
+			      convsbuf, &convs_length);
+  if (convs == NULL)
     {
       if (foldeds != foldedsbuf)
 	{
diff --git a/lib/uniconv.h b/lib/uniconv.h
index 4c565ad4f0..d364202e60 100644
--- a/lib/uniconv.h
+++ b/lib/uniconv.h
@@ -84,32 +84,32 @@ extern int
    array is filled with offsets into the result, i.e. the character starting
    at SRC[i] corresponds to the character starting at (*RESULTP)[OFFSETS[i]],
    and other offsets are set to (size_t)(-1).
-   *RESULTP and *LENGTHP should initially be a scratch buffer and its size,
-   or *RESULTP can initially be NULL.
+   RESULTBUF and *LENGTHP should initially be a scratch buffer and its size,
+   or RESULTBUF can be NULL.
    May erase the contents of the memory at *RESULTP.
-   Return value: 0 if successful, otherwise -1 and errno set.
-   If successful: The resulting string is stored in *RESULTP and its length
-   in *LENGTHP.  *RESULTP is set to a freshly allocated memory block, or is
-   unchanged if no dynamic memory allocation was necessary.
-   Particular errno values: EINVAL, EILSEQ, ENOMEM.  */
-extern int
+   If successful: The resulting string (non-NULL) is returned and its length
+   stored in *LENGTHP.  The resulting string is RESULTBUF if no dynamic memory
+   allocation was necessary, or a freshly allocated memory block otherwise.
+   In case of error: NULL is returned and errno is set.  Particular errno
+   values: EINVAL, EILSEQ, ENOMEM.  */
+extern char *
        u8_conv_to_encoding (const char *tocode,
 			    enum iconv_ilseq_handler handler,
 			    const uint8_t *src, size_t srclen,
 			    size_t *offsets,
-			    char **resultp, size_t *lengthp);
-extern int
+			    char *resultbuf, size_t *lengthp);
+extern char *
        u16_conv_to_encoding (const char *tocode,
 			     enum iconv_ilseq_handler handler,
 			     const uint16_t *src, size_t srclen,
 			     size_t *offsets,
-			     char **resultp, size_t *lengthp);
-extern int
+			     char *resultbuf, size_t *lengthp);
+extern char *
        u32_conv_to_encoding (const char *tocode,
 			     enum iconv_ilseq_handler handler,
 			     const uint32_t *src, size_t srclen,
 			     size_t *offsets,
-			     char **resultp, size_t *lengthp);
+			     char *resultbuf, size_t *lengthp);
 
 /* Converts a NUL terminated string from a given encoding.
    The result is malloc allocated, or NULL (with errno set) in case of error.
diff --git a/lib/uniconv/u-conv-to-enc.h b/lib/uniconv/u-conv-to-enc.h
index 144ea40171..f8840c2577 100644
--- a/lib/uniconv/u-conv-to-enc.h
+++ b/lib/uniconv/u-conv-to-enc.h
@@ -14,15 +14,17 @@
    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-int
+char *
 FUNC (const char *tocode,
       enum iconv_ilseq_handler handler,
       const UNIT *src, size_t srclen,
       size_t *offsets,
-      char **resultp, size_t *lengthp)
+      char *resultbuf, size_t *lengthp)
 {
 #if HAVE_UTF_NAME
   size_t *scaled_offsets;
+  char *result;
+  size_t length;
   int retval;
 
   if (offsets != NULL && srclen > 0)
@@ -32,42 +34,59 @@ FUNC (const char *tocode,
       if (scaled_offsets == NULL)
 	{
 	  errno = ENOMEM;
-	  return -1;
+	  return NULL;
 	}
     }
   else
     scaled_offsets = NULL;
 
+  result = resultbuf;
+  length = *lengthp;
   retval = mem_iconveha ((const char *) src, srclen * sizeof (UNIT),
 			 UTF_NAME, tocode,
 			 handler == iconveh_question_mark, handler,
-			 scaled_offsets, resultp, lengthp);
+			 scaled_offsets, &result, &length);
+  if (retval < 0)
+    {
+      int saved_errno = errno;
+      free (scaled_offsets);
+      errno = saved_errno;
+      return NULL;
+    }
 
   if (offsets != NULL)
     {
-      if (retval >= 0)
-	{
-	  /* Convert scaled_offsets[srclen * sizeof (UNIT)] to
-	     offsets[srclen].  */
-	  size_t i;
+      /* Convert scaled_offsets[srclen * sizeof (UNIT)] to
+	 offsets[srclen].  */
+      size_t i;
 
-	  for (i = 0; i < srclen; i++)
-	    offsets[i] = scaled_offsets[i * sizeof (UNIT)];
-	}
+      for (i = 0; i < srclen; i++)
+	offsets[i] = scaled_offsets[i * sizeof (UNIT)];
       free (scaled_offsets);
     }
-  return retval;
+
+  if (result == NULL) /* when (resultbuf == NULL && length == 0)  */
+    {
+      result = (char *) malloc (1);
+      if (result == NULL)
+	{
+	  errno = ENOMEM;
+	  return NULL;
+	}
+    }
+  *lengthp = length;
+  return result;
 #else
   uint8_t tmpbuf[4096];
   size_t tmpbufsize = SIZEOF (tmpbuf);
   uint8_t *utf8_src;
   size_t utf8_srclen;
   size_t *scaled_offsets;
-  int retval;
+  char *result;
 
   utf8_src = U_TO_U8 (src, srclen, tmpbuf, &tmpbufsize);
   if (utf8_src == NULL)
-    return -1;
+    return NULL;
   utf8_srclen = tmpbufsize;
 
   if (offsets != NULL && utf8_srclen > 0)
@@ -78,22 +97,22 @@ FUNC (const char *tocode,
 	  if (utf8_src != tmpbuf)
 	    free (utf8_src);
 	  errno = ENOMEM;
-	  return -1;
+	  return NULL;
 	}
     }
   else
     scaled_offsets = NULL;
 
-  retval = u8_conv_to_encoding (tocode, handler, utf8_src, utf8_srclen,
-				scaled_offsets, resultp, lengthp);
-  if (retval < 0)
+  result = u8_conv_to_encoding (tocode, handler, utf8_src, utf8_srclen,
+				scaled_offsets, resultbuf, lengthp);
+  if (result == NULL)
     {
       int saved_errno = errno;
       free (scaled_offsets);
       if (utf8_src != tmpbuf)
 	free (utf8_src);
       errno = saved_errno;
-      return -1;
+      return NULL;
     }
   if (offsets != NULL)
     {
@@ -134,6 +153,6 @@ FUNC (const char *tocode,
     }
   if (utf8_src != tmpbuf)
     free (utf8_src);
-  return retval;
+  return result;
 #endif
 }
diff --git a/lib/uniconv/u8-conv-to-enc.c b/lib/uniconv/u8-conv-to-enc.c
index 85404d4be9..5aec163a11 100644
--- a/lib/uniconv/u8-conv-to-enc.c
+++ b/lib/uniconv/u8-conv-to-enc.c
@@ -29,47 +29,66 @@
 #include "striconveha.h"
 #include "unistr.h"
 
-int
+char *
 u8_conv_to_encoding (const char *tocode,
 		     enum iconv_ilseq_handler handler,
 		     const uint8_t *src, size_t srclen,
 		     size_t *offsets,
-		     char **resultp, size_t *lengthp)
+		     char *resultbuf, size_t *lengthp)
 {
-  char *result;
-
   if (STRCASEEQ (tocode, "UTF-8", 'U','T','F','-','8',0,0,0,0))
     {
+      char *result;
+
       /* Conversion from UTF-8 to UTF-8.  No need to go through iconv().  */
 #if CONFIG_UNICODE_SAFETY
       if (u8_check (src, srclen))
 	{
 	  errno = EILSEQ;
-	  return -1;
+	  return NULL;
 	}
 #endif
 
       /* Memory allocation.  */
-      if ((*resultp != NULL && *lengthp >= srclen) || srclen == 0)
-	result = *resultp;
+      if (resultbuf != NULL && *lengthp >= srclen)
+	result = resultbuf;
       else
 	{
-	  result = (char *) malloc (srclen);
+	  result = (char *) malloc (srclen > 0 ? srclen : 1);
 	  if (result == NULL)
 	    {
 	      errno = ENOMEM;
-	      return -1;
+	      return NULL;
 	    }
 	}
 
       memcpy (result, (const char *) src, srclen);
-      *resultp = result;
       *lengthp = srclen;
-      return 0;
+      return result;
     }
   else
-    return mem_iconveha ((const char *) src, srclen,
-			 "UTF-8", tocode,
-			 handler == iconveh_question_mark, handler,
-			 offsets, resultp, lengthp);
+    {
+      char *result = resultbuf;
+      size_t length = *lengthp;
+      int retval =
+	mem_iconveha ((const char *) src, srclen,
+		      "UTF-8", tocode,
+		      handler == iconveh_question_mark, handler,
+		      offsets, &result, &length);
+
+      if (retval < 0)
+	return NULL;
+
+      if (result == NULL) /* when (resultbuf == NULL && length == 0)  */
+	{
+	  result = (char *) malloc (1);
+	  if (result == NULL)
+	    {
+	      errno = ENOMEM;
+	      return NULL;
+	    }
+	}
+      *lengthp = length;
+      return result;
+    }
 }
diff --git a/lib/uninorm/u-normxfrm.h b/lib/uninorm/u-normxfrm.h
index 60036b1058..6ed1e3c360 100644
--- a/lib/uninorm/u-normxfrm.h
+++ b/lib/uninorm/u-normxfrm.h
@@ -25,7 +25,6 @@ FUNC (const UNIT *s, size_t n, uninorm_t nf,
   char convsbuf[2048];
   char *convs;
   size_t convs_length;
-  int ret;
   char *result;
 
   /* Normalize the Unicode string.  */
@@ -36,14 +35,13 @@ FUNC (const UNIT *s, size_t n, uninorm_t nf,
     return NULL;
 
   /* Convert it to locale encoding.  */
-  convs = convsbuf;
   convs_length = sizeof (convsbuf) - 1;
-  ret = U_CONV_TO_ENCODING (locale_charset (),
-			    iconveh_error,
-			    norms, norms_length,
-			    NULL,
-			    &convs, &convs_length);
-  if (ret < 0)
+  convs = U_CONV_TO_ENCODING (locale_charset (),
+			      iconveh_error,
+			      norms, norms_length,
+			      NULL,
+			      convsbuf, &convs_length);
+  if (convs == NULL)
     {
       if (norms != normsbuf)
 	{
diff --git a/lib/vasnprintf.c b/lib/vasnprintf.c
index ce4e44b7b3..51375eb4e5 100644
--- a/lib/vasnprintf.c
+++ b/lib/vasnprintf.c
@@ -1799,18 +1799,18 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp,
 			size_t converted_len = allocated - length;
 #  if DCHAR_IS_TCHAR
 			/* Convert from UTF-8 to locale encoding.  */
-			if (u8_conv_to_encoding (locale_charset (),
-						 iconveh_question_mark,
-						 arg, arg_end - arg, NULL,
-						 &converted, &converted_len)
-			    < 0)
+			converted =
+			  u8_conv_to_encoding (locale_charset (),
+					       iconveh_question_mark,
+					       arg, arg_end - arg, NULL,
+					       converted, &converted_len);
 #  else
 			/* Convert from UTF-8 to UTF-16/UTF-32.  */
 			converted =
 			  U8_TO_DCHAR (arg, arg_end - arg,
 				       converted, &converted_len);
-			if (converted == NULL)
 #  endif
+			if (converted == NULL)
 			  {
 			    int saved_errno = errno;
 			    if (!(result == resultbuf || result == NULL))
@@ -1927,18 +1927,18 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp,
 			size_t converted_len = allocated - length;
 #  if DCHAR_IS_TCHAR
 			/* Convert from UTF-16 to locale encoding.  */
-			if (u16_conv_to_encoding (locale_charset (),
-						  iconveh_question_mark,
-						  arg, arg_end - arg, NULL,
-						  &converted, &converted_len)
-			    < 0)
+			converted =
+			  u16_conv_to_encoding (locale_charset (),
+						iconveh_question_mark,
+						arg, arg_end - arg, NULL,
+						converted, &converted_len);
 #  else
 			/* Convert from UTF-16 to UTF-8/UTF-32.  */
 			converted =
 			  U16_TO_DCHAR (arg, arg_end - arg,
 					converted, &converted_len);
-			if (converted == NULL)
 #  endif
+			if (converted == NULL)
 			  {
 			    int saved_errno = errno;
 			    if (!(result == resultbuf || result == NULL))
@@ -2055,18 +2055,18 @@ VASNPRINTF (DCHAR_T *resultbuf, size_t *lengthp,
 			size_t converted_len = allocated - length;
 #  if DCHAR_IS_TCHAR
 			/* Convert from UTF-32 to locale encoding.  */
-			if (u32_conv_to_encoding (locale_charset (),
-						  iconveh_question_mark,
-						  arg, arg_end - arg, NULL,
-						  &converted, &converted_len)
-			    < 0)
+			converted =
+			  u32_conv_to_encoding (locale_charset (),
+						iconveh_question_mark,
+						arg, arg_end - arg, NULL,
+						converted, &converted_len);
 #  else
 			/* Convert from UTF-32 to UTF-8/UTF-16.  */
 			converted =
 			  U32_TO_DCHAR (arg, arg_end - arg,
 					converted, &converted_len);
-			if (converted == NULL)
 #  endif
+			if (converted == NULL)
 			  {
 			    int saved_errno = errno;
 			    if (!(result == resultbuf || result == NULL))