Never call an object with a this ptr that is nullv5.12.0-beta4v5.12.0-beta3

Task-number: QTBUG-67936
Change-Id: Ie12c87f8aef30ebca887ad357393c86417d7d742
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

2 files changed, 14 insertions, 7 deletions

diff --git a/src/3rdparty/javascriptcore/JavaScriptCore/API/JSStringRef.cpp b/src/3rdparty/javascriptcore/JavaScriptCore/API/JSStringRef.cpp
index 8e236e4..fc337ef 100644
--- a/src/3rdparty/javascriptcore/JavaScriptCore/API/JSStringRef.cpp
+++ b/src/3rdparty/javascriptcore/JavaScriptCore/API/JSStringRef.cpp
@@ -67,18 +67,18 @@ void JSStringRelease(JSStringRef string)
 
 size_t JSStringGetLength(JSStringRef string)
 {
-    return string->length();
+    return string ? string->length() : 0;
 }
 
 const JSChar* JSStringGetCharactersPtr(JSStringRef string)
 {
-    return string->characters();
+    return string ? string->characters() : nullptr;
 }
 
 size_t JSStringGetMaximumUTF8CStringSize(JSStringRef string)
 {
     // Any UTF8 character > 3 bytes encodes as a UTF16 surrogate pair.
-    return string->length() * 3 + 1; // + 1 for terminating '\0'
+    return string ? string->length() * 3 + 1 : 1; // + 1 for terminating '\0'
 }
 
 size_t JSStringGetUTF8CString(JSStringRef string, char* buffer, size_t bufferSize)
@@ -87,8 +87,11 @@ size_t JSStringGetUTF8CString(JSStringRef string, char* buffer, size_t bufferSiz
         return 0;
 
     char* p = buffer;
-    const UChar* d = string->characters();
-    ConversionResult result = convertUTF16ToUTF8(&d, d + string->length(), &p, p + bufferSize - 1, true);
+    ConversionResult result = conversionOK;
+    if (string) {
+        const UChar* d = string->characters();
+        result = convertUTF16ToUTF8(&d, d + string->length(), &p, p + bufferSize - 1, true);
+    }
     *p++ = '\0';
     if (result != conversionOK && result != targetExhausted)
         return 0;
@@ -98,6 +101,10 @@ size_t JSStringGetUTF8CString(JSStringRef string, char* buffer, size_t bufferSiz
 
 bool JSStringIsEqual(JSStringRef a, JSStringRef b)
 {
+    if (!a)
+        return (!b || b->length() == 0);
+    if (!b)
+        return (!a || a->length() == 0);
     unsigned len = a->length();
     return len == b->length() && 0 == memcmp(a->characters(), b->characters(), len * sizeof(UChar));
 }
diff --git a/src/3rdparty/javascriptcore/JavaScriptCore/API/OpaqueJSString.h b/src/3rdparty/javascriptcore/JavaScriptCore/API/OpaqueJSString.h
index 473c815..6aa7b99 100644
--- a/src/3rdparty/javascriptcore/JavaScriptCore/API/OpaqueJSString.h
+++ b/src/3rdparty/javascriptcore/JavaScriptCore/API/OpaqueJSString.h
@@ -47,8 +47,8 @@ struct OpaqueJSString : public ThreadSafeShared<OpaqueJSString> {
 
     static PassRefPtr<OpaqueJSString> create(const JSC::UString&);
 
-    UChar* characters() { return this ? m_characters : 0; }
-    unsigned length() { return this ? m_length : 0; }
+    UChar* characters() { return m_characters; }
+    unsigned length() { return m_length; }
 
     JSC::UString ustring() const;
     JSC::Identifier identifier(JSC::JSGlobalData*) const;