Bug 1510028 - Add null check to avoid crash due to nsDependentCString(null). r=mkmelin

mailnews/base/util/nsMsgI18N.cpp

@@ -166,9 +166,9 @@ void nsMsgI18NTextFileCharset(nsACString& aCharset)
 char * nsMsgI18NEncodeMimePartIIStr(const char *header, bool structured, const char *charset, int32_t fieldnamelen, bool usemime)
 {
   // No MIME, convert to the outgoing mail charset.
-  if (false == usemime) {
+  if (!usemime) {
     nsAutoCString convertedStr;
-    if (NS_SUCCEEDED(nsMsgI18NConvertFromUnicode(nsDependentCString(charset),
+    if (NS_SUCCEEDED(nsMsgI18NConvertFromUnicode(charset ? nsDependentCString(charset) : EmptyCString(),
                                                  NS_ConvertUTF8toUTF16(header),
                                                  convertedStr)))
       return PL_strdup(convertedStr.get());

mailnews/compose/src/nsMsgCompose.cpp

@@ -1295,6 +1295,7 @@ NS_IMETHODIMP nsMsgCompose::SendMsg(MSG_DeliverMode deliverMode, nsIMsgIdentity
   nsString contentType = (m_composeHTML) ? NS_LITERAL_STRING("text/html"):
                                            NS_LITERAL_STRING("text/plain");
   nsString msgBody;
+  const char *charset = m_compFields->GetCharacterSet();
   if (m_editor)
   {
     // Reset message body previously stored in the compose fields
@@ -1302,8 +1303,6 @@ NS_IMETHODIMP nsMsgCompose::SendMsg(MSG_DeliverMode deliverMode, nsIMsgIdentity
     // therefore a casting is required.
     m_compFields->SetBody((const char *)nullptr);
 
-    const char *charset = m_compFields->GetCharacterSet();
-
     uint32_t flags = nsIDocumentEncoder::OutputCRLineBreak |
                      nsIDocumentEncoder::OutputLFLineBreak;
 
@@ -1336,7 +1335,7 @@ NS_IMETHODIMP nsMsgCompose::SendMsg(MSG_DeliverMode deliverMode, nsIMsgIdentity
     bool isAsciiOnly = NS_IsAscii(static_cast<const char16_t*>(msgBody.get()));
     // Convert body to mail charset
     nsCString outCString;
-    rv = nsMsgI18NConvertFromUnicode(nsDependentCString(m_compFields->GetCharacterSet()),
+    rv = nsMsgI18NConvertFromUnicode(charset ? nsDependentCString(charset) : EmptyCString(),
                                      msgBody, outCString, true);
     if (m_compFields->GetForceMsgEncoding())
       isAsciiOnly = false;
@@ -1353,10 +1352,10 @@ NS_IMETHODIMP nsMsgCompose::SendMsg(MSG_DeliverMode deliverMode, nsIMsgIdentity
         {
           bool disableFallback = false;
           nsCOMPtr<nsIPrefBranch> prefBranch (do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
-          if (prefBranch)
+          if (prefBranch && charset)
           {
             nsCString prefName("mailnews.disable_fallback_to_utf8.");
-            prefName.Append(m_compFields->GetCharacterSet());
+            prefName.Append(charset);
             prefBranch->GetBoolPref(prefName.get(), &disableFallback);
           }
           if (!disableFallback)

mailnews/import/outlook/src/MapiMessage.cpp

@@ -1273,9 +1273,11 @@ void CMapiMessageHeaders::CHeaderField::GetUnfoldedString(nsString& dest,
   if (m_fbody_utf8)
     CopyUTF8toUTF16(unfolded, dest);
   else
-    nsMsgI18NConvertToUnicode(nsDependentCString(fallbackCharset),
-                                                 unfolded,
-                                                 dest);
+    nsMsgI18NConvertToUnicode(fallbackCharset ?
+                                nsDependentCString(fallbackCharset) :
+                                EmptyCString(),
+                              unfolded,
+                              dest);
 }
 
 ////////////////////////////////////////

mailnews/import/outlook/src/nsOutlookCompose.cpp

@@ -279,7 +279,8 @@ nsresult nsOutlookCompose::ComposeTheMessage(nsMsgDeliverMode mode, CMapiMessage
   }
 
   nsCString bodyA;
-  nsMsgI18NConvertFromUnicode(nsDependentCString(msg.GetBodyCharset()), bodyW, bodyA);
+  const char *charset = msg.GetBodyCharset();
+  nsMsgI18NConvertFromUnicode(charset ? nsDependentCString(charset) : EmptyCString(), bodyW, bodyA);
 
   nsCOMPtr<nsIImportService> impService(do_GetService(NS_IMPORTSERVICE_CONTRACTID, &rv));
   NS_ENSURE_SUCCESS(rv, rv);

mailnews/mime/src/mimedrft.cpp

@@ -349,7 +349,7 @@ CreateCompositionFields(const char        *from,
 
   if (from) {
     nsMsgI18NConvertRawBytesToUTF16(nsDependentCString(from),
-                                    nsDependentCString(charset),
+                                    charset ? nsDependentCString(charset) : EmptyCString(),
                                     outString);
     cFields->SetFrom(outString);
   }
@@ -361,28 +361,28 @@ CreateCompositionFields(const char        *from,
 
   if (reply_to) {
     nsMsgI18NConvertRawBytesToUTF16(nsDependentCString(reply_to),
-                                    nsDependentCString(charset),
+                                    charset ? nsDependentCString(charset) : EmptyCString(),
                                     outString);
     cFields->SetReplyTo(outString);
   }
 
   if (to) {
     nsMsgI18NConvertRawBytesToUTF16(nsDependentCString(to),
-                                    nsDependentCString(charset),
+                                    charset ? nsDependentCString(charset) : EmptyCString(),
                                     outString);
     cFields->SetTo(outString);
   }
 
   if (cc) {
     nsMsgI18NConvertRawBytesToUTF16(nsDependentCString(cc),
-                                    nsDependentCString(charset),
+                                    charset ? nsDependentCString(charset) : EmptyCString(),
                                     outString);
     cFields->SetCc(outString);
   }
 
   if (bcc) {
     nsMsgI18NConvertRawBytesToUTF16(nsDependentCString(bcc),
-                                    nsDependentCString(charset),
+                                    charset ? nsDependentCString(charset) : EmptyCString(),
                                     outString);
     cFields->SetBcc(outString);
   }

mailnews/mime/src/mimehdrs.cpp

@@ -40,7 +40,9 @@ MimeHeaders_convert_header_value(MimeDisplayOptions *opt, nsCString &value,
   {
     nsAutoCString output;
     nsMsgI18NConvertRawBytesToUTF8(value,
-                                   nsDependentCString(opt->default_charset),
+                                   opt->default_charset ?
+                                     nsDependentCString(opt->default_charset) :
+                                     EmptyCString(),
                                    output);
     value.Assign(output);
     return;