From bbb0ff36dbb57461c3086c6e729aa3acf7a559ec Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Sat, 26 Sep 2009 13:31:27 +0000
Subject: [PATCH] Fix another off-by-1 bug in wxMBConv::ToWChar().
When converting a fixed number of characters we need to take any NULs inside
the buffer being converted into account for our return value -- but this
wasn't done and converting 2 characters 'x' and '\0' returned only 1, even if
the length 2 was explicitly specified.
Fix this bug and add a unit test checking for it.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62141 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
src/common/strconv.cpp | 37 ++++++++++++++++++-------------------
tests/strings/unicode.cpp | 15 ++++++++++++---
2 files changed, 30 insertions(+), 22 deletions(-)
diff --git a/src/common/strconv.cpp b/src/common/strconv.cpp
index c0d9daf06b..7ad34c9ccf 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;
@@ -333,7 +332,7 @@ wxMBConv::FromWChar(char *dst, size_t dstLen,
return wxCONV_FAILED;
dstWritten += lenChunk;
- if ( src+lenChunk < srcEnd || isNulTerminated )
+ if ( src + lenChunk < srcEnd || isNulTerminated )
dstWritten += lenNul;
if ( dst )
@@ -345,7 +344,7 @@ wxMBConv::FromWChar(char *dst, size_t dstLen,
return wxCONV_FAILED;
dst += lenChunk;
- if ( src+lenChunk < srcEnd || isNulTerminated )
+ if ( src + lenChunk < srcEnd || isNulTerminated )
dst += lenNul;
}
}
diff --git a/tests/strings/unicode.cpp b/tests/strings/unicode.cpp
index 18bd0f286f..1a4e4c412b 100644
--- a/tests/strings/unicode.cpp
+++ b/tests/strings/unicode.cpp
@@ -139,7 +139,7 @@ private:
CPPUNIT_TEST_SUITE( UnicodeTestCase );
CPPUNIT_TEST( ToFromAscii );
CPPUNIT_TEST( ConstructorsWithConversion );
- CPPUNIT_TEST( ConversionEmpty );
+ CPPUNIT_TEST( ConversionFixed );
CPPUNIT_TEST( ConversionWithNULs );
CPPUNIT_TEST( ConversionUTF7 );
CPPUNIT_TEST( ConversionUTF8 );
@@ -153,7 +153,7 @@ private:
void ToFromAscii();
void ConstructorsWithConversion();
- void ConversionEmpty();
+ void ConversionFixed();
void ConversionWithNULs();
void ConversionUTF7();
void ConversionUTF8();
@@ -238,7 +238,7 @@ void UnicodeTestCase::ConstructorsWithConversion()
CPPUNIT_ASSERT( s5 != "SomethingElse" );
}
-void UnicodeTestCase::ConversionEmpty()
+void UnicodeTestCase::ConversionFixed()
{
size_t len;
@@ -249,6 +249,15 @@ void UnicodeTestCase::ConversionEmpty()
#endif // wxUSE_UNICODE/!wxUSE_UNICODE
CPPUNIT_ASSERT_EQUAL( 0, len );
+
+#if wxUSE_UNICODE
+ // check that when we convert a fixed number of characters we obtain the
+ // expected return value
+ CPPUNIT_ASSERT_EQUAL( 0, wxConvLibc.ToWChar(NULL, 0, "", 0) );
+ CPPUNIT_ASSERT_EQUAL( 1, wxConvLibc.ToWChar(NULL, 0, "x", 1) );
+ CPPUNIT_ASSERT_EQUAL( 2, wxConvLibc.ToWChar(NULL, 0, "x", 2) );
+ CPPUNIT_ASSERT_EQUAL( 2, wxConvLibc.ToWChar(NULL, 0, "xy", 2) );
+#endif // wxUSE_UNICODE
}
void UnicodeTestCase::ConversionWithNULs()
--
2.47.2