Pasting text copied from Linux results in doubled lines (#7144)

text/plain;charset=utf-8 clipboard format.

This results in double lines when pasting text copied from Linux to
Windows because the Windows client converts line endings and expects
only LF.

Co-authored-by: Pedro Navarro <pnavarro@netflix.com>

src/lib/platform/XWindowsClipboard.cpp

@@ -83,9 +83,9 @@ XWindowsClipboard::XWindowsClipboard(Display* display,
                                 "application/x-moz-nativehtml"));
     m_converters.push_back(new XWindowsClipboardBMPConverter(m_display));
     m_converters.push_back(new XWindowsClipboardUTF8Converter(m_display,
-                                "text/plain;charset=UTF-8"));
+                                "text/plain;charset=UTF-8", true));
     m_converters.push_back(new XWindowsClipboardUTF8Converter(m_display,
-                                "text/plain;charset=utf-8"));
+                                "text/plain;charset=utf-8", true));
     m_converters.push_back(new XWindowsClipboardUTF8Converter(m_display,
                                 "UTF8_STRING"));
     m_converters.push_back(new XWindowsClipboardUCS2Converter(m_display,

src/lib/platform/XWindowsClipboardUTF8Converter.cpp

@@ -18,13 +18,15 @@
 
 #include "platform/XWindowsClipboardUTF8Converter.h"
 
+#include <algorithm>
+
 //
 // XWindowsClipboardUTF8Converter
 //
 
 XWindowsClipboardUTF8Converter::XWindowsClipboardUTF8Converter(
-                Display* display, const char* name) :
+                Display* display, const char* name, bool normalize) :
-    m_atom(XInternAtom(display, name, False))
+    m_atom(XInternAtom(display, name, False)), m_normalize(normalize)
 {
     // do nothing
 }
@@ -52,6 +54,13 @@ XWindowsClipboardUTF8Converter::getDataSize() const
     return 8;
 }
 
+static
+bool
+isCR(char ch)
+{
+    return (ch == '\r');
+}
+
 String
 XWindowsClipboardUTF8Converter::fromIClipboard(const String& data) const
 {
@@ -61,5 +70,22 @@ XWindowsClipboardUTF8Converter::fromIClipboard(const String& data) const
 String
 XWindowsClipboardUTF8Converter::toIClipboard(const String& data) const
 {
+    // https://bugzilla.mozilla.org/show_bug.cgi?id=1547595
+    // GTK normalizes the clipboard's line endings to CRLF (\r\n) internally.
+    // When sending the raw data to other systems, like Windows, where \n is
+    // converted to \r\n we end up with \r\r\n, resulting in double lines when
+    // pasting.
+    //
+    // This seems to happen only when the clipboard format is
+    // text/plain;charset=utf8 and not when it's UTF8_STRING.
+    // When normalize clipboard is set, any \r present in the string is removed
+
+    if (m_normalize) {
+        String copy = data;
+
+        copy.erase(std::remove_if(copy.begin(), copy.end(), isCR), copy.end());
+        return copy;
+    }
+
     return data;
 }

src/lib/platform/XWindowsClipboardUTF8Converter.h

@@ -26,7 +26,7 @@ public:
     /*!
     \c name is converted to an atom and that is reported by getAtom().
     */
-    XWindowsClipboardUTF8Converter(Display* display, const char* name);
+    XWindowsClipboardUTF8Converter(Display* display, const char* name, bool normalize = false);
     virtual ~XWindowsClipboardUTF8Converter();
 
     // IXWindowsClipboardConverter overrides
@@ -39,4 +39,5 @@ public:
 
 private:
     Atom                m_atom;
+    bool                m_normalize;
 };