X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/40ac5040ce7de5b2849c01543cace239ad8a7639..3b9ba64cce90f096763d70915fd459bfdf6a57d3:/src/common/strconv.cpp

diff --git a/src/common/strconv.cpp b/src/common/strconv.cpp
index c0d9daf06b..599048e9e2 100644
--- a/src/common/strconv.cpp
+++ b/src/common/strconv.cpp
@@ -216,7 +216,7 @@ wxMBConv::ToWChar(wchar_t *dst, size_t dstLen,
     // all the complication come from the fact that this function, for
     // historical reasons, must behave in 2 subtly different ways when it's
     // called with a fixed number of characters and when it's called for the
-    // entire NUL-terminated string: in the former case (srcEnd == NULL) we
+    // entire NUL-terminated string: in the former case (srcEnd != NULL) we
     // must count all characters we convert, NUL or not; but in the latter we
     // do not count the trailing NUL -- but still count all the NULs inside the
     // string
@@ -258,11 +258,13 @@ wxMBConv::ToWChar(wchar_t *dst, size_t dstLen,
         if ( !srcEnd )
         {
             // we convert just one chunk in this case as this is the entire
-            // string anyhow
+            // string anyhow (and we don't count the trailing NUL in this case)
             break;
         }
 
-        // advance the input pointer past the end of this chunk
+        // advance the input pointer past the end of this chunk: notice that we
+        // will always stop before srcEnd because we know that the chunk is
+        // always properly NUL-terminated
         while ( NotAllNULs(src, nulLen) )
         {
             // notice that we must skip over multiple bytes here as we suppose
@@ -272,23 +274,20 @@ wxMBConv::ToWChar(wchar_t *dst, size_t dstLen,
             src += nulLen;
         }
 
-        src += nulLen; // skipping over its terminator as well
+        // if the buffer ends before this NUL, we shouldn't count it in our
+        // output so skip the code below
+        if ( src == srcEnd )
+            break;
+
+        // do count this terminator as it's inside the buffer we convert
+        dstWritten++;
+        if ( dst )
+            dst++;
+
+        src += nulLen; // skip the terminator itself
 
-        // note that ">=" (and not just "==") is needed here as the terminator
-        // we skipped just above could be inside or just after the buffer
-        // delimited by srcEnd
         if ( src >= srcEnd )
             break;
-
-        // if we got here then this wasn't the last chunk in this string and
-        // hence we must count an extra char for L'\0' even when converting a
-        // fixed number of characters
-        if ( srcEnd )
-        {
-            dstWritten++;
-            if ( dst )
-                dst++;
-        }
     }
 
     return dstWritten;
@@ -324,16 +323,22 @@ wxMBConv::FromWChar(char *dst, size_t dstLen,
     const size_t lenNul = GetMBNulLen();
     for ( const wchar_t * const srcEnd = src + srcLen;
           src < srcEnd;
-          src += wxWcslen(src) + 1 /* skip L'\0' too */ )
+          src++ /* skip L'\0' too */ )
     {
         // try to convert the current chunk
         size_t lenChunk = WC2MB(NULL, src, 0);
-
         if ( lenChunk == wxCONV_FAILED )
             return wxCONV_FAILED;
 
         dstWritten += lenChunk;
-        if ( src+lenChunk < srcEnd || isNulTerminated )
+
+        const wchar_t * const
+            chunkEnd = isNulTerminated ? srcEnd - 1 : src + wxWcslen(src);
+
+        // our return value accounts for the trailing NUL(s), unlike that of
+        // WC2MB(), however don't do it for the last NUL we artificially added
+        // ourselves above
+        if ( chunkEnd < srcEnd )
             dstWritten += lenNul;
 
         if ( dst )
@@ -341,13 +346,42 @@ wxMBConv::FromWChar(char *dst, size_t dstLen,
             if ( dstWritten > dstLen )
                 return wxCONV_FAILED;
 
-            if ( WC2MB(dst, src, lenChunk + lenNul) == wxCONV_FAILED )
+            // if we know that there is enough space in the destination buffer
+            // (because we accounted for lenNul in dstWritten above), we can
+            // convert directly in place -- but otherwise we need another
+            // temporary buffer to ensure that we don't overwrite the output
+            wxCharBuffer dstBuf;
+            char *dstTmp;
+            if ( chunkEnd == srcEnd )
+            {
+                dstBuf = wxCharBuffer(lenChunk + lenNul - 1);
+                dstTmp = dstBuf.data();
+            }
+            else
+            {
+                dstTmp = dst;
+            }
+
+            if ( WC2MB(dstTmp, src, lenChunk + lenNul) == wxCONV_FAILED )
                 return wxCONV_FAILED;
 
+            if ( dstTmp != dst )
+            {
+                // copy everything up to but excluding the terminating NUL(s)
+                // into the real output buffer
+                memcpy(dst, dstTmp, lenChunk);
+
+                // micro-optimization: if dstTmp != dst it means that chunkEnd
+                // == srcEnd and so we're done, no need to update anything below
+                break;
+            }
+
             dst += lenChunk;
-            if ( src+lenChunk < srcEnd || isNulTerminated )
+            if ( chunkEnd < srcEnd )
                 dst += lenNul;
         }
+
+        src = chunkEnd;
     }
 
     return dstWritten;
@@ -2145,9 +2179,9 @@ wxMBConv_iconv::wxMBConv_iconv(const char *name)
         wxLogTrace(TRACE_STRCONV, wxT("Looking for wide char codeset:"));
 
 #if wxUSE_FONTMAP
-        const wxChar **names = wxFontMapperBase::GetAllEncodingNames(WC_ENC);
+        const wxChar *const *names = wxFontMapperBase::GetAllEncodingNames(WC_ENC);
 #else // !wxUSE_FONTMAP
-        static const wxChar *names_static[] =
+        static const wxChar *const names_static[] =
         {
 #if SIZEOF_WCHAR_T == 4
             wxT("UCS-4"),
@@ -2156,7 +2190,7 @@ wxMBConv_iconv::wxMBConv_iconv(const char *name)
 #endif
             NULL
         };
-        const wxChar **names = names_static;
+        const wxChar *const *names = names_static;
 #endif // wxUSE_FONTMAP/!wxUSE_FONTMAP
 
         for ( ; *names && ms_wcCharsetName.empty(); ++names )
@@ -3069,7 +3103,7 @@ wxMBConv *wxCSConv::DoCreate() const
                 delete conv;
             }
 
-            const wxChar** names = wxFontMapperBase::GetAllEncodingNames(encoding);
+            const wxChar* const* names = wxFontMapperBase::GetAllEncodingNames(encoding);
             // CS : in case this does not return valid names (eg for MacRoman)
             // encoding got a 'failure' entry in the cache all the same,
             // although it just has to be created using a different method, so