UTF-8 text codec should be able to convert data when fed one by one byte.

When the input data is fed to utf-8 by one byte it couldn't parse
the BOM correctly. So we wait until the BOM is composed into a code point and check it afterwards.

Reviewed-by: Olivier Goffart

1 files changed, 10 insertions, 1 deletions

diff --git a/src/corelib/codecs/qutfcodec.cpp b/src/corelib/codecs/qutfcodec.cpp
index 6611315..27c0572 100644
--- a/src/corelib/codecs/qutfcodec.cpp
+++ b/src/corelib/codecs/qutfcodec.cpp
@@ -184,7 +184,10 @@ void QUtf8Codec::convertToUnicode(QString *target, const char *chars, int len, C
                 uc = (uc << 6) | (ch & 0x3f);
                 need--;
                 if (!need) {
-                    if (uc > 0xffff && uc < 0x110000) {
+                    // utf-8 bom composes into 0xfeff code point
+                    if (!headerdone && uc == 0xfeff) {
+                        // dont do anything, just skip the BOM
+                    } else if (uc > 0xffff && uc < 0x110000) {
                         // surrogate pair
                         uc -= 0x10000;
                         unsigned short high = uc/0x400 + 0xd800;
@@ -206,6 +209,7 @@ void QUtf8Codec::convertToUnicode(QString *target, const char *chars, int len, C
                     } else {
                         *qch++ = uc;
                     }
+                    headerdone = true;
                 }
             } else {
                 // error
@@ -213,15 +217,18 @@ void QUtf8Codec::convertToUnicode(QString *target, const char *chars, int len, C
                 *qch++ = replacement;
                 ++invalid;
                 need = 0;
+                headerdone = true;
             }
         } else {
             if (ch < 128) {
                 *qch++ = QLatin1Char(ch);
+                headerdone = true;
             } else if ((ch & 0xe0) == 0xc0) {
                 uc = ch & 0x1f;
                 need = 1;
                 error = i;
                 min_uc = 0x80;
+                headerdone = true;
             } else if ((ch & 0xf0) == 0xe0) {
                 uc = ch & 0x0f;
                 need = 2;
@@ -232,10 +239,12 @@ void QUtf8Codec::convertToUnicode(QString *target, const char *chars, int len, C
                 need = 3;
                 error = i;
                 min_uc = 0x10000;
+                headerdone = true;
             } else {
                 // error
                 *qch++ = replacement;
                 ++invalid;
+                headerdone = true;
             }
         }
     }