Index: scribus/pageitem_textframe.cpp
===================================================================
--- scribus/pageitem_textframe.cpp	(revision 27777)
+++ scribus/pageitem_textframe.cpp	(working copy)
@@ -2572,11 +2572,20 @@
 								OFs = 0;
 						}
 
+						// A line ending in one of these breaks should only be
+						// force-justified if the break falls mid-paragraph -
+						// if it's also the paragraph's own last character,
+						// this line is the paragraph's last line, and should
+						// be left alone like any other last line of a
+						// justified paragraph (natural width, not stretched).
+						bool breakEndsParagraph = (a + 1 >= itemText.length()) || (itemText.text(a + 1) == SpecialChars::PARSEP);
+
 						if (style.alignment() == ParagraphStyle::Extended
 							|| (style.alignment() == ParagraphStyle::Justified
 								&&  (itemText.text(a) == SpecialChars::LINEBREAK ||
 									 itemText.text(a) == SpecialChars::FRAMEBREAK ||
 									 itemText.text(a) == SpecialChars::COLBREAK)
+								&&  !breakEndsParagraph
 								&&  (current.lineData.lastCluster - 1 >= 0)
 								&&  !itemText.text(glyphClusters[current.lineData.lastCluster - 1].lastChar()).isSpace()))
 						{

Index: scribus/pageitem_textframe.cpp
===================================================================
--- scribus/pageitem_textframe.cpp	(revision 27777)
+++ scribus/pageitem_textframe.cpp	(working copy)
@@ -2580,6 +2580,15 @@
 								&&  (current.lineData.lastCluster - 1 >= 0)
 								&&  !itemText.text(glyphClusters[current.lineData.lastCluster - 1].lastChar()).isSpace()))
 						{
+							if (itemText.text(a) == SpecialChars::LINEBREAK ||
+								itemText.text(a) == SpecialChars::FRAMEBREAK ||
+								itemText.text(a) == SpecialChars::COLBREAK)
+							{
+								bool nextIsParsepOrEnd = (a + 1 >= itemText.length()) || (itemText.text(a + 1) == SpecialChars::PARSEP);
+								qDebug() << "[JUSTIFYDIAG-1] forced justifyLine() at a=" << a
+									<< "breakChar=" << itemText.text(a).unicode()
+									<< "nextIsParsepOrEnd=" << nextIsParsepOrEnd;
+							}
 							current.justifyLine(style);
 						}
 						else
@@ -3005,6 +3014,15 @@
 						 itemText.text(a) == SpecialChars::COLBREAK)
 					&&  !itemText.text(a).isSpace()))
 			{
+				if (itemText.text(a) == SpecialChars::LINEBREAK ||
+					itemText.text(a) == SpecialChars::FRAMEBREAK ||
+					itemText.text(a) == SpecialChars::COLBREAK)
+				{
+					bool nextIsParsepOrEnd = (a + 1 >= itemText.length()) || (itemText.text(a + 1) == SpecialChars::PARSEP);
+					qDebug() << "[JUSTIFYDIAG-2] forced justifyLine() at a=" << a
+						<< "breakChar=" << itemText.text(a).unicode()
+						<< "nextIsParsepOrEnd=" << nextIsParsepOrEnd;
+				}
 				current.justifyLine(style);
 			}
 			else