Update expat to 2.2.0 to fix CVE vulnerability.

third_party/expat/files/lib/xmltok.c.origin

 /* Copyright (c) 1998, 1999 Thai Open Source Software Center Ltd
    See the file COPYING for copying permission.
 */
 
 #include <stddef.h>
 
-#ifdef COMPILED_FROM_DSP
+#ifdef WIN32
 #include "winconfig.h"
 #elif defined(MACOS_CLASSIC)
 #include "macconfig.h"
 #elif defined(__amigaos__)
 #include "amigaconfig.h"
 #elif defined(__WATCOMC__)
 #include "watcomconfig.h"
 #else
 #ifdef HAVE_EXPAT_CONFIG_H
 #include <expat_config.h>
 #endif
-#endif /* ndef COMPILED_FROM_DSP */
+#endif /* ndef WIN32 */
 
 #include "expat_external.h"
 #include "internal.h"
 #include "xmltok.h"
 #include "nametab.h"
 
 #ifdef XML_DTD
 #define IGNORE_SECTION_TOK_VTABLE , PREFIX(ignoreSectionTok)
 #else
 #define IGNORE_SECTION_TOK_VTABLE /* as nothing */
 #endif
 
 #define VTABLE1 \
   { PREFIX(prologTok), PREFIX(contentTok), \
     PREFIX(cdataSectionTok) IGNORE_SECTION_TOK_VTABLE }, \
   { PREFIX(attributeValueTok), PREFIX(entityValueTok) }, \
   PREFIX(sameName), \
   PREFIX(nameMatchesAscii), \
   PREFIX(nameLength), \
   PREFIX(skipS), \
   PREFIX(getAtts), \
   PREFIX(charRefNumber), \
   PREFIX(predefinedEntityName), \
   PREFIX(updatePosition), \
   PREFIX(isPublicId)
 
 #define VTABLE VTABLE1, PREFIX(toUtf8), PREFIX(toUtf16)
 
 #define UCS2_GET_NAMING(pages, hi, lo) \
-   (namingBitmap[(pages[hi] << 3) + ((lo) >> 5)] & (1 << ((lo) & 0x1F)))
+   (namingBitmap[(pages[hi] << 3) + ((lo) >> 5)] & (1u << ((lo) & 0x1F)))
 
 /* A 2 byte UTF-8 representation splits the characters 11 bits between
    the bottom 5 and 6 bits of the bytes.  We need 8 bits to index into
    pages, 3 bits to add to that index and 5 bits to generate the mask.
 */
 #define UTF8_GET_NAMING2(pages, byte) \
     (namingBitmap[((pages)[(((byte)[0]) >> 2) & 7] << 3) \
                       + ((((byte)[0]) & 3) << 1) \
                       + ((((byte)[1]) >> 5) & 1)] \
-         & (1 << (((byte)[1]) & 0x1F)))
+         & (1u << (((byte)[1]) & 0x1F)))
 
 /* A 3 byte UTF-8 representation splits the characters 16 bits between
    the bottom 4, 6 and 6 bits of the bytes.  We need 8 bits to index
    into pages, 3 bits to add to that index and 5 bits to generate the
    mask.
 */
 #define UTF8_GET_NAMING3(pages, byte) \
   (namingBitmap[((pages)[((((byte)[0]) & 0xF) << 4) \
                              + ((((byte)[1]) >> 2) & 0xF)] \
                        << 3) \
                       + ((((byte)[1]) & 3) << 1) \
                       + ((((byte)[2]) >> 5) & 1)] \
-         & (1 << (((byte)[2]) & 0x1F)))
+         & (1u << (((byte)[2]) & 0x1F)))
 
 #define UTF8_GET_NAMING(pages, p, n) \
   ((n) == 2 \
   ? UTF8_GET_NAMING2(pages, (const unsigned char *)(p)) \
   : ((n) == 3 \
      ? UTF8_GET_NAMING3(pages, (const unsigned char *)(p)) \
      : 0))
 
 /* Detection of invalid UTF-8 sequences is based on Table 3.1B
    of Unicode 3.2: http://www.unicode.org/unicode/reports/tr28/
@@ skipping 32 matching lines @@
   || \
   ((*p) == 0xF0 \
     ? \
     (p)[1] < 0x90 || ((p)[1] & 0xC0) == 0xC0 \
     : \
     ((p)[1] & 0x80) == 0 \
     || \
     ((*p) == 0xF4 ? (p)[1] > 0x8F : ((p)[1] & 0xC0) == 0xC0)))
 
 static int PTRFASTCALL
-isNever(const ENCODING *enc, const char *p)
+isNever(const ENCODING *UNUSED_P(enc), const char *UNUSED_P(p))
 {
   return 0;
 }
 
 static int PTRFASTCALL
-utf8_isName2(const ENCODING *enc, const char *p)
+utf8_isName2(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_GET_NAMING2(namePages, (const unsigned char *)p);
 }
 
 static int PTRFASTCALL
-utf8_isName3(const ENCODING *enc, const char *p)
+utf8_isName3(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_GET_NAMING3(namePages, (const unsigned char *)p);
 }
 
 #define utf8_isName4 isNever
 
 static int PTRFASTCALL
-utf8_isNmstrt2(const ENCODING *enc, const char *p)
+utf8_isNmstrt2(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_GET_NAMING2(nmstrtPages, (const unsigned char *)p);
 }
 
 static int PTRFASTCALL
-utf8_isNmstrt3(const ENCODING *enc, const char *p)
+utf8_isNmstrt3(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_GET_NAMING3(nmstrtPages, (const unsigned char *)p);
 }
 
 #define utf8_isNmstrt4 isNever
 
 static int PTRFASTCALL
-utf8_isInvalid2(const ENCODING *enc, const char *p)
+utf8_isInvalid2(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_INVALID2((const unsigned char *)p);
 }
 
 static int PTRFASTCALL
-utf8_isInvalid3(const ENCODING *enc, const char *p)
+utf8_isInvalid3(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_INVALID3((const unsigned char *)p);
 }
 
 static int PTRFASTCALL
-utf8_isInvalid4(const ENCODING *enc, const char *p)
+utf8_isInvalid4(const ENCODING *UNUSED_P(enc), const char *p)
 {
   return UTF8_INVALID4((const unsigned char *)p);
 }
 
 struct normal_encoding {
   ENCODING enc;
   unsigned char type[256];
 #ifdef XML_MIN_SIZE
   int (PTRFASTCALL *byteType)(const ENCODING *, const char *);
   int (PTRFASTCALL *isNameMin)(const ENCODING *, const char *);
@@ skipping 33 matching lines @@
  E ## isName2, \
  E ## isName3, \
  E ## isName4, \
  E ## isNmstrt2, \
  E ## isNmstrt3, \
  E ## isNmstrt4, \
  E ## isInvalid2, \
  E ## isInvalid3, \
  E ## isInvalid4
 
+#define NULL_VTABLE \
+ /* isName2 */ NULL, \
+ /* isName3 */ NULL, \
+ /* isName4 */ NULL, \
+ /* isNmstrt2 */ NULL, \
+ /* isNmstrt3 */ NULL, \
+ /* isNmstrt4 */ NULL, \
+ /* isInvalid2 */ NULL, \
+ /* isInvalid3 */ NULL, \
+ /* isInvalid4 */ NULL
+
 static int FASTCALL checkCharRefNumber(int);
 
 #include "xmltok_impl.h"
 #include "ascii.h"
 
 #ifdef XML_MIN_SIZE
 #define sb_isNameMin isNever
 #define sb_isNmstrtMin isNever
 #endif
 
@@ skipping 76 matching lines @@
 #undef IS_NMSTRT_CHAR_MINBPC
 #undef IS_INVALID_CHAR
 
 enum {  /* UTF8_cvalN is value of masked first byte of N byte sequence */
   UTF8_cval1 = 0x00,
   UTF8_cval2 = 0xc0,
   UTF8_cval3 = 0xe0,
   UTF8_cval4 = 0xf0
 };
 
-static void PTRCALL
-utf8_toUtf8(const ENCODING *enc,
+void
+align_limit_to_full_utf8_characters(const char * from, const char ** fromLimRef)
+{
+  const char * fromLim = *fromLimRef;
+  size_t walked = 0;
+  for (; fromLim > from; fromLim--, walked++) {
+    const unsigned char prev = (unsigned char)fromLim[-1];
+    if ((prev & 0xf8u) == 0xf0u) { /* 4-byte character, lead by 0b11110xxx byte */
+      if (walked + 1 >= 4) {
+        fromLim += 4 - 1;
+        break;
+      } else {
+        walked = 0;
+      }
+    } else if ((prev & 0xf0u) == 0xe0u) { /* 3-byte character, lead by 0b1110xxxx byte */
+      if (walked + 1 >= 3) {
+        fromLim += 3 - 1;
+        break;
+      } else {
+        walked = 0;
+      }
+    } else if ((prev & 0xe0u) == 0xc0u) { /* 2-byte character, lead by 0b110xxxxx byte */
+      if (walked + 1 >= 2) {
+        fromLim += 2 - 1;
+        break;
+      } else {
+        walked = 0;
+      }
+    } else if ((prev & 0x80u) == 0x00u) { /* 1-byte character, matching 0b0xxxxxxx */
+      break;
+    }
+  }
+  *fromLimRef = fromLim;
+}
+
+static enum XML_Convert_Result PTRCALL
+utf8_toUtf8(const ENCODING *UNUSED_P(enc),
             const char **fromP, const char *fromLim,
             char **toP, const char *toLim)
 {
+  enum XML_Convert_Result res = XML_CONVERT_COMPLETED;
   char *to;
   const char *from;
   if (fromLim - *fromP > toLim - *toP) {
     /* Avoid copying partial characters. */
-    for (fromLim = *fromP + (toLim - *toP); fromLim > *fromP; fromLim--)
-      if (((unsigned char)fromLim[-1] & 0xc0) != 0x80)
-        break;
+    res = XML_CONVERT_OUTPUT_EXHAUSTED;
+    fromLim = *fromP + (toLim - *toP);
+    align_limit_to_full_utf8_characters(*fromP, &fromLim);
   }
-  for (to = *toP, from = *fromP; from != fromLim; from++, to++)
+  for (to = *toP, from = *fromP; (from < fromLim) && (to < toLim); from++, to++)
     *to = *from;
   *fromP = from;
   *toP = to;
+
+  if ((to == toLim) && (from < fromLim))
+    return XML_CONVERT_OUTPUT_EXHAUSTED;
+  else
+    return res;
 }
 
-static void PTRCALL
+static enum XML_Convert_Result PTRCALL
 utf8_toUtf16(const ENCODING *enc,
              const char **fromP, const char *fromLim,
              unsigned short **toP, const unsigned short *toLim)
 {
+  enum XML_Convert_Result res = XML_CONVERT_COMPLETED;
   unsigned short *to = *toP;
   const char *from = *fromP;
-  while (from != fromLim && to != toLim) {
+  while (from < fromLim && to < toLim) {
     switch (((struct normal_encoding *)enc)->type[(unsigned char)*from]) {
     case BT_LEAD2:
+      if (fromLim - from < 2) {
+        res = XML_CONVERT_INPUT_INCOMPLETE;
+        break;
+      }
       *to++ = (unsigned short)(((from[0] & 0x1f) << 6) | (from[1] & 0x3f));
       from += 2;
       break;
     case BT_LEAD3:
+      if (fromLim - from < 3) {
+        res = XML_CONVERT_INPUT_INCOMPLETE;
+        break;
+      }
       *to++ = (unsigned short)(((from[0] & 0xf) << 12)
                                | ((from[1] & 0x3f) << 6) | (from[2] & 0x3f));
       from += 3;
       break;
     case BT_LEAD4:
       {
         unsigned long n;
-        if (to + 1 == toLim)
+        if (toLim - to < 2) {
+          res = XML_CONVERT_OUTPUT_EXHAUSTED;
           goto after;
+        }
+        if (fromLim - from < 4) {
+          res = XML_CONVERT_INPUT_INCOMPLETE;
+          goto after;
+        }
         n = ((from[0] & 0x7) << 18) | ((from[1] & 0x3f) << 12)
             | ((from[2] & 0x3f) << 6) | (from[3] & 0x3f);
         n -= 0x10000;
         to[0] = (unsigned short)((n >> 10) | 0xD800);
         to[1] = (unsigned short)((n & 0x3FF) | 0xDC00);
         to += 2;
         from += 4;
       }
       break;
     default:
       *to++ = *from++;
       break;
     }
   }
 after:
   *fromP = from;
   *toP = to;
+  return res;
 }
 
 #ifdef XML_NS
 static const struct normal_encoding utf8_encoding_ns = {
   { VTABLE1, utf8_toUtf8, utf8_toUtf16, 1, 1, 0 },
   {
 #include "asciitab.h"
 #include "utf8tab.h"
   },
   STANDARD_VTABLE(sb_) NORMAL_VTABLE(utf8_)
@@ skipping 28 matching lines @@
   { VTABLE1, utf8_toUtf8, utf8_toUtf16, 1, 1, 0 },
   {
 #define BT_COLON BT_NMSTRT
 #include "iasciitab.h"
 #undef BT_COLON
 #include "utf8tab.h"
   },
   STANDARD_VTABLE(sb_) NORMAL_VTABLE(utf8_)
 };
 
-static void PTRCALL
-latin1_toUtf8(const ENCODING *enc,
+static enum XML_Convert_Result PTRCALL
+latin1_toUtf8(const ENCODING *UNUSED_P(enc),
               const char **fromP, const char *fromLim,
               char **toP, const char *toLim)
 {
   for (;;) {
     unsigned char c;
     if (*fromP == fromLim)
-      break;
+      return XML_CONVERT_COMPLETED;
     c = (unsigned char)**fromP;
     if (c & 0x80) {
       if (toLim - *toP < 2)
-        break;
+        return XML_CONVERT_OUTPUT_EXHAUSTED;
       *(*toP)++ = (char)((c >> 6) | UTF8_cval2);
       *(*toP)++ = (char)((c & 0x3f) | 0x80);
       (*fromP)++;
     }
     else {
       if (*toP == toLim)
-        break;
+        return XML_CONVERT_OUTPUT_EXHAUSTED;
       *(*toP)++ = *(*fromP)++;
     }
   }
 }
 
-static void PTRCALL
-latin1_toUtf16(const ENCODING *enc,
+static enum XML_Convert_Result PTRCALL
+latin1_toUtf16(const ENCODING *UNUSED_P(enc),
                const char **fromP, const char *fromLim,
                unsigned short **toP, const unsigned short *toLim)
 {
-  while (*fromP != fromLim && *toP != toLim)
+  while (*fromP < fromLim && *toP < toLim)
     *(*toP)++ = (unsigned char)*(*fromP)++;
+
+  if ((*toP == toLim) && (*fromP < fromLim))
+    return XML_CONVERT_OUTPUT_EXHAUSTED;
+  else
+    return XML_CONVERT_COMPLETED;
 }
 
 #ifdef XML_NS
 
 static const struct normal_encoding latin1_encoding_ns = {
   { VTABLE1, latin1_toUtf8, latin1_toUtf16, 1, 0, 0 },
   {
 #include "asciitab.h"
 #include "latin1tab.h"
   },
-  STANDARD_VTABLE(sb_)
+  STANDARD_VTABLE(sb_) NULL_VTABLE
 };
 
 #endif
 
 static const struct normal_encoding latin1_encoding = {
   { VTABLE1, latin1_toUtf8, latin1_toUtf16, 1, 0, 0 },
   {
 #define BT_COLON BT_NMSTRT
 #include "asciitab.h"
 #undef BT_COLON
 #include "latin1tab.h"
   },
-  STANDARD_VTABLE(sb_)
+  STANDARD_VTABLE(sb_) NULL_VTABLE
 };
 
-static void PTRCALL
-ascii_toUtf8(const ENCODING *enc,
+static enum XML_Convert_Result PTRCALL
+ascii_toUtf8(const ENCODING *UNUSED_P(enc),
              const char **fromP, const char *fromLim,
              char **toP, const char *toLim)
 {
-  while (*fromP != fromLim && *toP != toLim)
+  while (*fromP < fromLim && *toP < toLim)
     *(*toP)++ = *(*fromP)++;
+
+  if ((*toP == toLim) && (*fromP < fromLim))
+    return XML_CONVERT_OUTPUT_EXHAUSTED;
+  else
+    return XML_CONVERT_COMPLETED;
 }
 
 #ifdef XML_NS
 
 static const struct normal_encoding ascii_encoding_ns = {
   { VTABLE1, ascii_toUtf8, latin1_toUtf16, 1, 1, 0 },
   {
 #include "asciitab.h"
 /* BT_NONXML == 0 */
   },
-  STANDARD_VTABLE(sb_)
+  STANDARD_VTABLE(sb_) NULL_VTABLE
 };
 
 #endif
 
 static const struct normal_encoding ascii_encoding = {
   { VTABLE1, ascii_toUtf8, latin1_toUtf16, 1, 1, 0 },
   {
 #define BT_COLON BT_NMSTRT
 #include "asciitab.h"
 #undef BT_COLON
 /* BT_NONXML == 0 */
   },
-  STANDARD_VTABLE(sb_)
+  STANDARD_VTABLE(sb_) NULL_VTABLE
 };
 
 static int PTRFASTCALL
 unicode_byte_type(char hi, char lo)
 {
   switch ((unsigned char)hi) {
   case 0xD8: case 0xD9: case 0xDA: case 0xDB:
     return BT_LEAD4;
   case 0xDC: case 0xDD: case 0xDE: case 0xDF:
     return BT_TRAIL;
   case 0xFF:
     switch ((unsigned char)lo) {
     case 0xFF:
     case 0xFE:
       return BT_NONXML;
     }
     break;
   }
   return BT_NONASCII;
 }
 
 #define DEFINE_UTF16_TO_UTF8(E) \
-static void  PTRCALL \
-E ## toUtf8(const ENCODING *enc, \
+static enum XML_Convert_Result  PTRCALL \
+E ## toUtf8(const ENCODING *UNUSED_P(enc), \
             const char **fromP, const char *fromLim, \
             char **toP, const char *toLim) \
 { \
-  const char *from; \
-  for (from = *fromP; from != fromLim; from += 2) { \
+  const char *from = *fromP; \
+  fromLim = from + (((fromLim - from) >> 1) << 1);  /* shrink to even */ \
+  for (; from < fromLim; from += 2) { \
     int plane; \
     unsigned char lo2; \
     unsigned char lo = GET_LO(from); \
     unsigned char hi = GET_HI(from); \
     switch (hi) { \
     case 0: \
       if (lo < 0x80) { \
         if (*toP == toLim) { \
           *fromP = from; \
-          return; \
+          return XML_CONVERT_OUTPUT_EXHAUSTED; \
         } \
         *(*toP)++ = lo; \
         break; \
       } \
       /* fall through */ \
     case 0x1: case 0x2: case 0x3: \
     case 0x4: case 0x5: case 0x6: case 0x7: \
       if (toLim -  *toP < 2) { \
         *fromP = from; \
-        return; \
+        return XML_CONVERT_OUTPUT_EXHAUSTED; \
       } \
       *(*toP)++ = ((lo >> 6) | (hi << 2) |  UTF8_cval2); \
       *(*toP)++ = ((lo & 0x3f) | 0x80); \
       break; \
     default: \
       if (toLim -  *toP < 3)  { \
         *fromP = from; \
-        return; \
+        return XML_CONVERT_OUTPUT_EXHAUSTED; \
       } \
       /* 16 bits divided 4, 6, 6 amongst 3 bytes */ \
       *(*toP)++ = ((hi >> 4) | UTF8_cval3); \
       *(*toP)++ = (((hi & 0xf) << 2) | (lo >> 6) | 0x80); \
       *(*toP)++ = ((lo & 0x3f) | 0x80); \
       break; \
     case 0xD8: case 0xD9: case 0xDA: case 0xDB: \
       if (toLim -  *toP < 4) { \
         *fromP = from; \
-        return; \
+        return XML_CONVERT_OUTPUT_EXHAUSTED; \
+      } \
+      if (fromLim - from < 4) { \
+        *fromP = from; \
+        return XML_CONVERT_INPUT_INCOMPLETE; \
       } \
       plane = (((hi & 0x3) << 2) | ((lo >> 6) & 0x3)) + 1; \
       *(*toP)++ = ((plane >> 2) | UTF8_cval4); \
       *(*toP)++ = (((lo >> 2) & 0xF) | ((plane & 0x3) << 4) | 0x80); \
       from += 2; \
       lo2 = GET_LO(from); \
       *(*toP)++ = (((lo & 0x3) << 4) \
                    | ((GET_HI(from) & 0x3) << 2) \
                    | (lo2 >> 6) \
                    | 0x80); \
       *(*toP)++ = ((lo2 & 0x3f) | 0x80); \
       break; \
     } \
   } \
   *fromP = from; \
+  if (from < fromLim) \
+    return XML_CONVERT_INPUT_INCOMPLETE; \
+  else \
+    return XML_CONVERT_COMPLETED; \
 }
 
 #define DEFINE_UTF16_TO_UTF16(E) \
-static void  PTRCALL \
-E ## toUtf16(const ENCODING *enc, \
+static enum XML_Convert_Result  PTRCALL \
+E ## toUtf16(const ENCODING *UNUSED_P(enc), \
              const char **fromP, const char *fromLim, \
              unsigned short **toP, const unsigned short *toLim) \
 { \
+  enum XML_Convert_Result res = XML_CONVERT_COMPLETED; \
+  fromLim = *fromP + (((fromLim - *fromP) >> 1) << 1);  /* shrink to even */ \
   /* Avoid copying first half only of surrogate */ \
   if (fromLim - *fromP > ((toLim - *toP) << 1) \
-      && (GET_HI(fromLim - 2) & 0xF8) == 0xD8) \
+      && (GET_HI(fromLim - 2) & 0xF8) == 0xD8) { \
     fromLim -= 2; \
-  for (; *fromP != fromLim && *toP != toLim; *fromP += 2) \
+    res = XML_CONVERT_INPUT_INCOMPLETE; \
+  } \
+  for (; *fromP < fromLim && *toP < toLim; *fromP += 2) \
     *(*toP)++ = (GET_HI(*fromP) << 8) | GET_LO(*fromP); \
+  if ((*toP == toLim) && (*fromP < fromLim)) \
+    return XML_CONVERT_OUTPUT_EXHAUSTED; \
+  else \
+    return res; \
 }
 
 #define SET2(ptr, ch) \
   (((ptr)[0] = ((ch) & 0xff)), ((ptr)[1] = ((ch) >> 8)))
 #define GET_LO(ptr) ((unsigned char)(ptr)[0])
 #define GET_HI(ptr) ((unsigned char)(ptr)[1])
 
 DEFINE_UTF16_TO_UTF8(little2_)
 DEFINE_UTF16_TO_UTF16(little2_)
 
@@ skipping 96 matching lines @@
 #if BYTEORDER == 1234
     1
 #else
     0
 #endif
   },
   {
 #include "asciitab.h"
 #include "latin1tab.h"
   },
-  STANDARD_VTABLE(little2_)
+  STANDARD_VTABLE(little2_) NULL_VTABLE
 };
 
 #endif
 
 static const struct normal_encoding little2_encoding = {
   { VTABLE, 2, 0,
 #if BYTEORDER == 1234
     1
 #else
     0
 #endif
   },
   {
 #define BT_COLON BT_NMSTRT
 #include "asciitab.h"
 #undef BT_COLON
 #include "latin1tab.h"
   },
-  STANDARD_VTABLE(little2_)
+  STANDARD_VTABLE(little2_) NULL_VTABLE
 };
 
 #if BYTEORDER != 4321
 
 #ifdef XML_NS
 
 static const struct normal_encoding internal_little2_encoding_ns = {
   { VTABLE, 2, 0, 1 },
   {
 #include "iasciitab.h"
 #include "latin1tab.h"
   },
-  STANDARD_VTABLE(little2_)
+  STANDARD_VTABLE(little2_) NULL_VTABLE
 };
 
 #endif
 
 static const struct normal_encoding internal_little2_encoding = {
   { VTABLE, 2, 0, 1 },
   {
 #define BT_COLON BT_NMSTRT
 #include "iasciitab.h"
 #undef BT_COLON
 #include "latin1tab.h"
   },
-  STANDARD_VTABLE(little2_)
+  STANDARD_VTABLE(little2_) NULL_VTABLE
 };
 
 #endif
 
 
 #define BIG2_BYTE_TYPE(enc, p) \
  ((p)[0] == 0 \
   ? ((struct normal_encoding *)(enc))->type[(unsigned char)(p)[1]] \
   : unicode_byte_type((p)[0], (p)[1]))
 #define BIG2_BYTE_TO_ASCII(enc, p) ((p)[0] == 0 ? (p)[1] : -1)
@@ skipping 75 matching lines @@
 #if BYTEORDER == 4321
   1
 #else
   0
 #endif
   },
   {
 #include "asciitab.h"
 #include "latin1tab.h"
   },
-  STANDARD_VTABLE(big2_)
+  STANDARD_VTABLE(big2_) NULL_VTABLE
 };
 
 #endif
 
 static const struct normal_encoding big2_encoding = {
   { VTABLE, 2, 0,
 #if BYTEORDER == 4321
   1
 #else
   0
 #endif
   },
   {
 #define BT_COLON BT_NMSTRT
 #include "asciitab.h"
 #undef BT_COLON
 #include "latin1tab.h"
   },
-  STANDARD_VTABLE(big2_)
+  STANDARD_VTABLE(big2_) NULL_VTABLE
 };
 
 #if BYTEORDER != 1234
 
 #ifdef XML_NS
 
 static const struct normal_encoding internal_big2_encoding_ns = {
   { VTABLE, 2, 0, 1 },
   {
 #include "iasciitab.h"
 #include "latin1tab.h"
   },
-  STANDARD_VTABLE(big2_)
+  STANDARD_VTABLE(big2_) NULL_VTABLE
 };
 
 #endif
 
 static const struct normal_encoding internal_big2_encoding = {
   { VTABLE, 2, 0, 1 },
   {
 #define BT_COLON BT_NMSTRT
 #include "iasciitab.h"
 #undef BT_COLON
 #include "latin1tab.h"
   },
-  STANDARD_VTABLE(big2_)
+  STANDARD_VTABLE(big2_) NULL_VTABLE
 };
 
 #endif
 
 #undef PREFIX
 
 static int FASTCALL
 streqci(const char *s1, const char *s2)
 {
   for (;;) {
     char c1 = *s1++;
     char c2 = *s2++;
     if (ASCII_a <= c1 && c1 <= ASCII_z)
       c1 += ASCII_A - ASCII_a;
     if (ASCII_a <= c2 && c2 <= ASCII_z)
       c2 += ASCII_A - ASCII_a;
     if (c1 != c2)
       return 0;
     if (!c1)
       break;
   }
   return 1;
 }
 
 static void PTRCALL
-initUpdatePosition(const ENCODING *enc, const char *ptr,
+initUpdatePosition(const ENCODING *UNUSED_P(enc), const char *ptr,
                    const char *end, POSITION *pos)
 {
   normal_updatePosition(&utf8_encoding.enc, ptr, end, pos);
 }
 
 static int
 toAscii(const ENCODING *enc, const char *ptr, const char *end)
 {
   char buf[1];
   char *p = buf;
@@ skipping 329 matching lines @@
 }
 
 static int PTRFASTCALL
 unknown_isInvalid(const ENCODING *enc, const char *p)
 {
   const struct unknown_encoding *uenc = AS_UNKNOWN_ENCODING(enc);
   int c = uenc->convert(uenc->userData, p);
   return (c & ~0xFFFF) || checkCharRefNumber(c) < 0;
 }
 
-static void PTRCALL
+static enum XML_Convert_Result PTRCALL
 unknown_toUtf8(const ENCODING *enc,
                const char **fromP, const char *fromLim,
                char **toP, const char *toLim)
 {
   const struct unknown_encoding *uenc = AS_UNKNOWN_ENCODING(enc);
   char buf[XML_UTF8_ENCODE_MAX];
   for (;;) {
     const char *utf8;
     int n;
     if (*fromP == fromLim)
-      break;
+      return XML_CONVERT_COMPLETED;
     utf8 = uenc->utf8[(unsigned char)**fromP];
     n = *utf8++;
     if (n == 0) {
       int c = uenc->convert(uenc->userData, *fromP);
       n = XmlUtf8Encode(c, buf);
       if (n > toLim - *toP)
-        break;
+        return XML_CONVERT_OUTPUT_EXHAUSTED;
       utf8 = buf;
       *fromP += (AS_NORMAL_ENCODING(enc)->type[(unsigned char)**fromP]
                  - (BT_LEAD2 - 2));
     }
     else {
       if (n > toLim - *toP)
-        break;
+        return XML_CONVERT_OUTPUT_EXHAUSTED;
       (*fromP)++;
     }
     do {
       *(*toP)++ = *utf8++;
     } while (--n != 0);
   }
 }
 
-static void PTRCALL
+static enum XML_Convert_Result PTRCALL
 unknown_toUtf16(const ENCODING *enc,
                 const char **fromP, const char *fromLim,
                 unsigned short **toP, const unsigned short *toLim)
 {
   const struct unknown_encoding *uenc = AS_UNKNOWN_ENCODING(enc);
-  while (*fromP != fromLim && *toP != toLim) {
+  while (*fromP < fromLim && *toP < toLim) {
     unsigned short c = uenc->utf16[(unsigned char)**fromP];
     if (c == 0) {
       c = (unsigned short)
           uenc->convert(uenc->userData, *fromP);
       *fromP += (AS_NORMAL_ENCODING(enc)->type[(unsigned char)**fromP]
                  - (BT_LEAD2 - 2));
     }
     else
       (*fromP)++;
     *(*toP)++ = c;
   }
+
+  if ((*toP == toLim) && (*fromP < fromLim))
+    return XML_CONVERT_OUTPUT_EXHAUSTED;
+  else
+    return XML_CONVERT_COMPLETED;
 }
 
 ENCODING *
 XmlInitUnknownEncoding(void *mem,
                        int *table,
                        CONVERTER convert,
                        void *userData)
 {
   int i;
   struct unknown_encoding *e = (struct unknown_encoding *)mem;
@@ skipping 143 matching lines @@
 static int
 initScan(const ENCODING * const *encodingTable,
          const INIT_ENCODING *enc,
          int state,
          const char *ptr,
          const char *end,
          const char **nextTokPtr)
 {
   const ENCODING **encPtr;
 
-  if (ptr == end)
+  if (ptr >= end)
     return XML_TOK_NONE;
   encPtr = enc->encPtr;
   if (ptr + 1 == end) {
     /* only a single byte available for auto-detection */
 #ifndef XML_DTD /* FIXME */
     /* a well-formed document entity must have more than one byte */
     if (state != XML_CONTENT_STATE)
       return XML_TOK_PARTIAL;
 #endif
     /* so we're parsing an external text entity... */
@@ skipping 125 matching lines @@
                          CONVERTER convert,
                          void *userData)
 {
   ENCODING *enc = XmlInitUnknownEncoding(mem, table, convert, userData);
   if (enc)
     ((struct normal_encoding *)enc)->type[ASCII_COLON] = BT_COLON;
   return enc;
 }
 
 #endif /* XML_NS */