diff --git a/Buffer.cc b/Buffer.cc
index 9ba4aa3..d72bb60 100644
--- a/Buffer.cc
+++ b/Buffer.cc
@@ -617,11 +617,16 @@ Buffer::OpenFromFile(const std::string &path, std::string &err)
 		return false;
 	}
 	(void) kte::syscall::Close(fd);
-	// Build the new content aside and swap it in only once complete: if the
-	// copy runs out of memory, the buffer keeps its old text (clearing first
-	// left an empty buffer that a later save wrote over the file).
-	// The bytes become the piece table's original storage, uncopied.
-	content_.AdoptOriginal(std::move(data)); // not used under PieceTable
+	// The bytes become the piece table's original storage, uncopied. If that
+	// runs out of memory the buffer keeps its old text (clearing first left
+	// an empty buffer that a later save wrote over the file).
+	try {
+		content_.AdoptOriginal(std::move(data));
+	} catch (const std::bad_alloc &) {
+		err = "File too large to load: " + norm;
+		kte::ErrorHandler::Instance().Error("Buffer", err, norm);
+		return false;
+	}
 	filename_         = norm;
 	is_file_backed_   = true;
 	is_virtual_       = false;
diff --git a/PieceTable.cc b/PieceTable.cc
index b550bad..bf220a9 100644
--- a/PieceTable.cc
+++ b/PieceTable.cc
@@ -206,13 +206,17 @@ PieceTable::Clear()
 void
 PieceTable::AdoptOriginal(std::string &&bytes)
 {
+	// Allocate before touching the current content: if this throws, the
+	// table is unchanged (everything below is non-throwing).
+	std::vector<Piece> pieces;
+	if (!bytes.empty())
+		pieces.push_back(Piece{Source::Original, 0, bytes.size()});
 	Clear();
 	std::string().swap(add_); // release a previous content's capacity
 	std::string().swap(materialized_);
 	original_   = std::move(bytes);
 	total_size_ = original_.size();
-	if (total_size_ > 0)
-		pieces_.push_back(Piece{Source::Original, 0, total_size_});
+	pieces_.swap(pieces);
 	version_++;
 }
 
diff --git a/PieceTable.h b/PieceTable.h
index 3033f48..7b9eb0e 100644
--- a/PieceTable.h
+++ b/PieceTable.h
@@ -86,6 +86,7 @@ public:
 
 	// Replace the content with `bytes`, taken over without copying (a loaded
 	// file). Undo spans into the old storage are invalidated, as by Clear().
+	// If it throws (std::bad_alloc), the content is unchanged.
 	void AdoptOriginal(std::string &&bytes);
 
 	// Accessors
diff --git a/QtFrontend.cc b/QtFrontend.cc
index 5915272..e9ff502 100644
--- a/QtFrontend.cc
+++ b/QtFrontend.cc
@@ -204,10 +204,21 @@ protected:
 						p.drawText(QPointF(col_x(col), baseline), QString::fromUtf8(d, static_cast<int>(n)));
 					};
 					auto draw_seg = [&](std::size_t s, std::size_t e, const QColor &color) {
-						// Only the visible columns: characters left of coloffs or
-						// right of the viewport are skipped.
+						// Only the visible columns: characters that end at or
+						// before coloffs, or start right of the viewport, are
+						// skipped. A tab or wide character straddling coloffs
+						// starts left of it; it is drawn at its own column and
+						// the clip cuts its left part.
+						const std::size_t first = s;
 						s = static_cast<std::size_t>(std::lower_bound(col_of.begin() + s, col_of.begin() + e,
 						                                              coloffs) - col_of.begin());
+						if (s > first && col_of[s] > coloffs) {
+							// The character before s ends past coloffs: back up to
+							// its first byte.
+							--s;
+							while (s > first && (static_cast<unsigned char>(line[s]) & 0xC0) == 0x80)
+								--s;
+						}
 						e = static_cast<std::size_t>(std::lower_bound(col_of.begin() + s, col_of.begin() + e,
 						                                              coloffs + vis_cols) - col_of.begin());
 						if (e <= s)