Two new options for QxtMailMessage: word wrap limit and preserve start spaces

word wrap limit sets maximum line length before it will be wrapped to next line.
default is 78 but for some clients it may be less (ex: thunderbird).
so if you are going to generate *.eml setWordWrapLimit will be helpful.

preserve start spaces controls start of wrapped line.
so if your very long line starts with 4 spaces then wrapped part will start
also with 4 spaces 0 if this feature is disabled.

src/network/qxtmailmessage.cpp

@@ -54,12 +54,15 @@ struct QxtMailMessagePrivate : public QSharedData
     QxtMailMessagePrivate(const QxtMailMessagePrivate& other)
             : QSharedData(other), rcptTo(other.rcptTo), rcptCc(other.rcptCc), rcptBcc(other.rcptBcc),
             subject(other.subject), body(other.body), sender(other.sender),
-            extraHeaders(other.extraHeaders), attachments(other.attachments) {}
+            extraHeaders(other.extraHeaders), attachments(other.attachments),
+            wordWrapLimit(78), preserveStartSpaces(false) {}
     QStringList rcptTo, rcptCc, rcptBcc;
     QString subject, body, sender;
     QHash<QString, QString> extraHeaders;
     QHash<QString, QxtMailAttachment> attachments;
     mutable QByteArray boundary;
+    int wordWrapLimit;
+    bool preserveStartSpaces;
 };
 
 class QxtRfc2822Parser
@@ -243,6 +246,25 @@ void QxtMailMessage::removeAttachment(const QString& filename)
     qxt_d->attachments.remove(filename);
 }
 
+/*!
+ * \brief Rewrites default 78 word wrap line length limit with new \a limit
+ */
+void QxtMailMessage::setWordWrapLimit(int limit)
+{
+    qxt_d->wordWrapLimit = limit;
+}
+
+/*!
+ * \brief Forces wrapped line to have the same indent as original.
+ *
+ * Ex: If your very long line starts with 4 sp. then wrapped part
+ *     will start with 4 sp too when this feature enabled
+ */
+void QxtMailMessage::setWordWrapPreserveStartSpaces(bool state)
+{
+    qxt_d->preserveStartSpaces = state;
+}
+
 QByteArray qxt_fold_mime_header(const QString& key, const QString& value, QTextCodec* latin1, const QByteArray& prefix)
 {
     QByteArray rv = "";
@@ -443,72 +465,59 @@ QByteArray QxtMailMessage::rfc2822() const
     {
         QByteArray b = latin1->fromUnicode(body());
         int len = b.length();
-        QByteArray line = "";
-        QByteArray word = "";
-        for (int i = 0; i < len; i++)
+        QByteArray line;
+        QByteArray word;
+        QByteArray spaces;
+        QByteArray startSpaces;
+        for (int i = 0; i <= len; i++)
         {
-            if (b[i] == '\n' || b[i] == '\r')
-            {
-                if (line.isEmpty()) 
-                {
-                    line = word;
-                    word = "";
-                }
-                else if (line.length() + word.length() + 1 <= 78)
-                {
-                    line = line + ' ' + word;
-                    word = "";
-                }
-                if(line[0] == '.')
-                    rv += ".";
-                rv += line + "\r\n";
-                if ((b[i+1] == '\n' || b[i+1] == '\r') && b[i] != b[i+1])
-                {
-                    // If we're looking at a CRLF pair, skip the second half
-                    i++;
-                }
-                line = word;
+            char ignoredChar = 0;
+            if (i != len) {
+                ignoredChar = b[i] == '\n'? '\r' : b[i] == '\r'? '\n' : 0;
             }
-            else if (b[i] == ' ')
-            {
-                if (line.length() + word.length() + 1 > 78)
-                {
+            if (!(ignoredChar || (i == len) || (b[i] == ' ') || (b[i] == '\t'))) {
+                // the char is part of word
+                if (word.isEmpty()) { // start of new word / end of spaces
+                    if (line.isEmpty()) {
+                        startSpaces = spaces;
+                    }
+                }
+                word += b[i];
+                continue;
+            }
+
+            // space char, so end of word or continuous spaces
+            if (!word.isEmpty()) { // start of new space area / end of word
+                if (line.length() + spaces.length() +
+                                        word.length() > qxt_d->wordWrapLimit) {
+                    // have to wrap word to next line
                     if(line[0] == '.')
                         rv += ".";
                     rv += line + "\r\n";
-                    line = word;
+                    if (qxt_d->preserveStartSpaces) {
+                        line = startSpaces + word;
+                    } else {
+                        line = word;
+                    }
+                } else { // no wrap required
+                    line += spaces + word;
                 }
-                else if (line.isEmpty())
-                {
-                    line = word;
-                }
-                else
-                {
-                    line = line + ' ' + word;
-                }
-                word = "";
+                word.clear();
+                spaces.clear();
             }
-            else
-            {
-                word += b[i];
+
+            if (ignoredChar || i == len) { // new line or eof
+                // trailing `spaces` are ignored here
+                if(line[0] == '.')
+                    rv += ".";
+                rv += line + "\r\n";
+                line.clear();
+                startSpaces.clear();
+                spaces.clear();
+            } else {
+                spaces += b[i];
             }
         }
-        if (line.length() + word.length() + 1 > 78)
-        {
-            if(line[0] == '.')
-                rv += ".";
-            rv += line + "\r\n";
-            line = word;
-        }
-        else if (!word.isEmpty())
-        {
-            line += ' ' + word;
-        }
-        if(!line.isEmpty()) {
-            if(line[0] == '.')
-                rv += ".";
-            rv += line + "\r\n";
-        }
     }
     else if (useQuotedPrintable)
     {

src/network/qxtmailmessage.h

@@ -82,6 +82,9 @@ public:
     void addAttachment(const QString& filename, const QxtMailAttachment& attach);
     void removeAttachment(const QString& filename);
 
+    void setWordWrapLimit(int limit);
+    void setWordWrapPreserveStartSpaces(bool state);
+
     QByteArray rfc2822() const;
     static QxtMailMessage fromRfc2822(const QByteArray&);