Add extra nano undo debug logging

Add_undo_stack_debug_logging.patch

Index: src/winio.c
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- src/winio.c	(date 1462931713000)
+++ src/winio.c	(revision )
@@ -3076,6 +3076,12 @@
 	(long)openfile->filebot->lineno, linepct,
 	(unsigned long)cur_xpt, (unsigned long)cur_lenpt, colpct,
 	(unsigned long)i, (unsigned long)openfile->totsize, charpct);
+
+#ifdef DEBUG
+    /* dump the undo stack to stderr every time the stats feature is invoked *
+     * debug build only */
+    debug_display_undo_stack();
+#endif
 }
 
 /* Unconditionally display the current cursor position. */
Index: src/proto.h
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- src/proto.h	(date 1462931713000)
+++ src/proto.h	(revision )
@@ -754,6 +754,9 @@
 void update_comment_undo(ssize_t lineno);
 bool comment_line(bool add_comment, filestruct *f, const char *comment_seq);
 #endif
+#ifdef DEBUG
+void debug_display_undo_stack();
+#endif
 #endif
 size_t get_totsize(const filestruct *begin, const filestruct *end);
 filestruct *fsfromline(ssize_t lineno);
Index: src/text.c
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- src/text.c	(date 1462931713000)
+++ src/text.c	(revision )
@@ -1239,6 +1239,53 @@
     openfile->last_action = action;
 }
 
+#ifdef DEBUG
+void debug_display_undo_stack() {
+    static const char *UNDOSTR[] = {
+	"ADD", "DEL", "BACK", "CUT", "CUT_EOF", "REPLACE",
+#ifndef DISABLE_WRAPPING
+	"SPLIT_BEGIN", "SPLIT_END",
+#endif
+#ifndef DISABLE_COMMENT
+	"COMMENT", "UNCOMMENT",
+#endif
+	"JOIN", "PASTE", "INSERT", "ENTER", "OTHER"
+    };
+    int i = 1;
+    undo *u = openfile->undotop;
+    fprintf(stderr, "\n");
+    if (!u)
+	fprintf(stderr, "UNDO: none\n");
+    while(u) {
+	if (u==openfile->current_undo)
+	    fprintf(stderr, "UNDO: ---- TOP -- undo: v redo: %s ------\n", (i>1 ? "^" : "none"));
+	fprintf(stderr, "UNDO %2d: %s at %d with %d:%s%.70s%s\n",
+	    i,
+	    UNDOSTR[(int)u->type],
+	    (int)u->lineno,
+	    (int)u->begin,
+	    u->strdata ? "\"" : "",
+	    u->strdata ? u->strdata : "NULL",
+	    u->strdata ? "\"" : ""
+	);
+	undo_group *grouping = u->grouping;
+	while(grouping) {
+	    fprintf(stderr, "        %ld to %ld\n", grouping->top_line, grouping->bottom_line);
+	    grouping = grouping->next;
+	}
+	i++;
+	u = u->next;
+	if (i>=50) {
+	    i = -1;
+	    fprintf(stderr, "UNDO: -- more items not shown --\n");
+	    break;
+	}
+    }
+    if (i>1 && 0==openfile->current_undo)
+	fprintf(stderr, "UNDO: ---- TOP -- undo: none redo: ^ ------\n");
+}
+#endif
+
 #ifndef DISABLE_COMMENT
 /* Add a comment undo action.  This should be called once for each use
  * of the comment or uncomment feature that modifies the document. */