[PATCH] files: clear original filename when the user toggles Append or Prepend

[Benno Schulenberg]

When the current filename is equal to the filename of the buffer,
then clear the filename, because the chances that the user wants
to append or prepend a file to itself are practically nil.

This fulfills https://savannah.gnu.org/bugs/?61243.
---
 src/files.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/files.c b/src/files.c
index 484852a9..f2d435a9 100644
--- a/src/files.c
+++ b/src/files.c
@@ -2194,9 +2194,13 @@ int do_writeout(bool exiting, bool withprompt)
                        TOGGLE(MAKE_BACKUP);
                        continue;
                } else if (func == prepend_void) {
+                       if (strcmp(answer, openfile->filename) == 0)
+                               given[0] = '\0';
                        method = (method == PREPEND) ? OVERWRITE : PREPEND;
                        continue;
                } else if (func == append_void) {
+                       if (strcmp(answer, openfile->filename) == 0)
+                               given[0] = '\0';
                        method = (method == APPEND) ? OVERWRITE : APPEND;
                        continue;
                }
-- 
2.29.3