Fix compilation with uclibc

The patch fixes the following errors and warnings raised by the
compilation of the library with uClibc:

encoding.c: In function ‘xmlEncInputChunk’:
encoding.c:2209:32: warning: comparison between pointer and integer
 2209 |     else if (handler->iconv_in != NULL) {
      |                                ^~
encoding.c: In function ‘xmlEncOutputChunk’:
encoding.c:2269:33: warning: comparison between pointer and integer
 2269 |     else if (handler->iconv_out != NULL) {
      |                                 ^~
encoding.c: In function ‘xmlCharEncCloseFunc’:
encoding.c:2681:29: warning: comparison between pointer and integer
 2681 |     if ((handler->iconv_out != NULL) || (handler->iconv_in != NULL)) {
      |                             ^~
encoding.c:2681:60: warning: comparison between pointer and integer
 2681 |     if ((handler->iconv_out != NULL) || (handler->iconv_in != NULL)) {
      |                                                            ^~
encoding.c:2683:32: warning: comparison between pointer and integer
 2683 |         if (handler->iconv_out != NULL) {
      |                                ^~
encoding.c:2686:32: error: assignment to ‘iconv_t’ {aka ‘long int’} from ‘void *’ makes integer from pointer without a cast [-Wint-conversion]
 2686 |             handler->iconv_out = NULL;
      |                                ^
encoding.c:2688:31: warning: comparison between pointer and integer
 2688 |         if (handler->iconv_in != NULL) {
      |                               ^~
encoding.c:2691:31: error: assignment to ‘iconv_t’ {aka ‘long int’} from ‘void *’ makes integer from pointer without a cast [-Wint-conversion]
 2691 |             handler->iconv_in = NULL;
      |                               ^
make[4]: *** [Makefile:1147: libxml2_la-encoding.lo] Error 1

Signed-off-by: Dario Binacchi <[email protected]>

Author: passgat

encoding.c

@@ -1264,7 +1264,7 @@ DECLARE_ISO_FUNCS(16)
 #endif /* LIBXML_ISO8859X_ENABLED */
 
 #ifdef LIBXML_ICONV_ENABLED
-  #define EMPTY_ICONV , (iconv_t) 0, (iconv_t) 0
+  #define EMPTY_ICONV , (iconv_t) -1, (iconv_t) -1
 #else
   #define EMPTY_ICONV
 #endif
@@ -1389,8 +1389,8 @@ xmlNewCharEncodingHandler(const char *name,
     handler->name = up;
 
 #ifdef LIBXML_ICONV_ENABLED
-    handler->iconv_in = NULL;
-    handler->iconv_out = NULL;
+    handler->iconv_in = (iconv_t) -1;
+    handler->iconv_out = (iconv_t) -1;
 #endif
 #ifdef LIBXML_ICU_ENABLED
     handler->uconv_in = NULL;
@@ -2200,7 +2200,7 @@ xmlEncInputChunk(xmlCharEncodingHandler *handler, unsigned char *out,
         }
     }
 #ifdef LIBXML_ICONV_ENABLED
-    else if (handler->iconv_in != NULL) {
+    else if (handler->iconv_in != (iconv_t) -1) {
         ret = xmlIconvWrapper(handler->iconv_in, out, outlen, in, inlen);
     }
 #endif /* LIBXML_ICONV_ENABLED */
@@ -2260,7 +2260,7 @@ xmlEncOutputChunk(xmlCharEncodingHandler *handler, unsigned char *out,
         }
     }
 #ifdef LIBXML_ICONV_ENABLED
-    else if (handler->iconv_out != NULL) {
+    else if (handler->iconv_out != (iconv_t) -1) {
         ret = xmlIconvWrapper(handler->iconv_out, out, outlen, in, inlen);
     }
 #endif /* LIBXML_ICONV_ENABLED */
@@ -2672,17 +2672,17 @@ xmlCharEncCloseFunc(xmlCharEncodingHandler *handler) {
      * Iconv handlers can be used only once, free the whole block.
      * and the associated icon resources.
      */
-    if ((handler->iconv_out != NULL) || (handler->iconv_in != NULL)) {
+    if ((handler->iconv_out != (iconv_t) -1) || (handler->iconv_in != (iconv_t) -1)) {
         tofree = 1;
-	if (handler->iconv_out != NULL) {
+	if (handler->iconv_out != (iconv_t) -1) {
 	    if (iconv_close(handler->iconv_out))
 		ret = -1;
-	    handler->iconv_out = NULL;
+	    handler->iconv_out = (iconv_t) -1;
 	}
-	if (handler->iconv_in != NULL) {
+	if (handler->iconv_in != (iconv_t) -1) {
 	    if (iconv_close(handler->iconv_in))
 		ret = -1;
-	    handler->iconv_in = NULL;
+	    handler->iconv_in = (iconv_t) -1;
 	}
     }
 #endif /* LIBXML_ICONV_ENABLED */