Fixes QIconvCodec::convertToUnicode()

We need to hang onto the internal state of the utf16 converter
object whenever converting a long string to unicode. This was
failing with the text stream class -- the first read was okay,
but subsequent reads could not be correctly converted to unicode.

cherry-picked from qt5/qtbase: 72c07311228ce6eefb460d7e5da3de24220ba81e

Change-Id: I794d78808ccd9deedcb406bfe46e373c18142d05
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 6 insertions, 1 deletions

diff --git a/src/corelib/codecs/qiconvcodec.cpp b/src/corelib/codecs/qiconvcodec.cpp
index 59c77ba..3b15d11 100644
--- a/src/corelib/codecs/qiconvcodec.cpp
+++ b/src/corelib/codecs/qiconvcodec.cpp
@@ -286,12 +286,16 @@ QString QIconvCodec::convertToUnicode(const char* chars, int len, ConverterState
         }
     } while (inBytesLeft != 0);
 
-    QString s = utf16Codec->toUnicode(ba.constData(), ba.size() - outBytesLeft);
+    QString s;
 
     if (convState) {
+        s = utf16Codec->toUnicode(ba.constData(), ba.size() - outBytesLeft, &state->internalState);
+
         convState->invalidChars = invalidCount;
         convState->remainingChars = remainingCount;
     } else {
+        s = utf16Codec->toUnicode(ba.constData(), ba.size() - outBytesLeft);
+
         // reset state
         iconv(state->cd, 0, &inBytesLeft, 0, &outBytesLeft);
     }
diff --git a/src/corelib/codecs/qiconvcodec_p.h b/src/corelib/codecs/qiconvcodec_p.h
index fb2d89e..d305210 100644
--- a/src/corelib/codecs/qiconvcodec_p.h
+++ b/src/corelib/codecs/qiconvcodec_p.h
@@ -87,6 +87,7 @@ public:
     public:
         IconvState(iconv_t x);
         ~IconvState();
+        ConverterState internalState;
         char *buffer;
         int bufferLen;
         iconv_t cd;