cutting: cover the corner cases where cut commands do not cut anything

Give the correct feedback in those cases and do not add an undo item.

This fixes both parts of https://savannah.gnu.org/bugs/?55396.

src/cut.c

@@ -203,7 +203,8 @@ void do_cut_prev_word(void)
 /* Delete a word rightward. */
 void do_cut_next_word(void)
 {
-	do_cutword(FALSE);
+	if (!nothing_needs_cutting(openfile->current_x > 0))
+		do_cutword(FALSE);
 }
 #endif /* !NANO_TINY */
 
@@ -356,14 +357,18 @@ void do_cut_text(bool copy_text, bool marked, bool cut_till_eof, bool append)
 }
 
 /* Return TRUE when a cut command would not actually cut anything: when
- * on an empty line at EOF, or when the mark covers zero characters. */
-bool nothing_needs_cutting(void)
+ * on an empty line at EOF, or when the mark covers zero characters, or
+ * (when test_cliff is TRUE) when the magic line would be cut. */
+bool nothing_needs_cutting(bool test_cliff)
 {
 	if ((openfile->current->next == NULL && openfile->current->data[0] == '\0'
 #ifndef NANO_TINY
 					&& openfile->mark == NULL) ||
 					(openfile->mark == openfile->current &&
-					openfile->mark_x == openfile->current_x
+					openfile->mark_x == openfile->current_x) ||
+					(test_cliff && openfile->current->data[openfile->current_x] == '\0' &&
+					((ISSET(NO_NEWLINES) && openfile->current == openfile->filebot) ||
+					(!ISSET(NO_NEWLINES) && openfile->current == openfile->filebot->prev))
 #endif
 					)) {
 #ifndef NANO_TINY
@@ -378,10 +383,10 @@ bool nothing_needs_cutting(void)
 /* Move text from the current buffer into the cutbuffer. */
 void do_cut_text_void(void)
 {
-	if (nothing_needs_cutting())
+#ifndef NANO_TINY
+	if (nothing_needs_cutting(ISSET(CUT_FROM_CURSOR) && openfile->mark == NULL))
 		return;
 
-#ifndef NANO_TINY
 	/* Only add a new undo item when the current item is not a CUT or when
 	 * the current cut is not contiguous with the previous cutting. */
 	if (openfile->last_action != CUT || openfile->current_undo == NULL ||
@@ -391,7 +396,8 @@ void do_cut_text_void(void)
 	do_cut_text(FALSE, openfile->mark, FALSE, FALSE);
 	update_undo(CUT);
 #else
-	do_cut_text(FALSE, FALSE, FALSE, FALSE);
+	if (!nothing_needs_cutting(FALSE))
+		do_cut_text(FALSE, FALSE, FALSE, FALSE);
 #endif
 }
 
@@ -430,7 +436,9 @@ void do_copy_text(void)
 /* Cut from the current cursor position to the end of the file. */
 void do_cut_till_eof(void)
 {
-	if (openfile->current->next == NULL && openfile->current->data[0] == '\0') {
+	if ((openfile->current == openfile->filebot && openfile->current->data[0] == '\0') ||
+				(!ISSET(NO_NEWLINES) && openfile->current->next == openfile->filebot &&
+				openfile->current->data[openfile->current_x] == '\0')) {
 		statusbar(_("Nothing was cut"));
 		return;
 	}
@@ -447,7 +455,7 @@ void zap_text(void)
 	filestruct *was_cutbuffer = cutbuffer;
 	filestruct *was_cutbottom = cutbottom;
 
-	if (nothing_needs_cutting())
+	if (nothing_needs_cutting(ISSET(CUT_FROM_CURSOR) && openfile->mark == NULL))
 		return;
 
 	/* Add a new undo item only when the current item is not a ZAP or when

src/proto.h

@@ -251,6 +251,7 @@ void do_cut_next_word(void);
 void cut_marked(bool *right_side_up);
 #endif
 void do_cut_text(bool copy_text, bool marked, bool cut_till_eof, bool append);
+bool nothing_needs_cutting(bool test_cliff);
 void do_cut_text_void(void);
 #ifndef NANO_TINY
 void do_copy_text(void);