From e9ca3ad9f64bf395233136f393e18d0b39666328 Mon Sep 17 00:00:00 2001
From: "Dirk-Jan C. Binnema" <djcb@djcbsoftware.nl>
Date: Sun, 1 Sep 2024 18:52:26 +0300
Subject: [PATCH] scanner: ignore emacs auto-saves

It's better to _not_ have auto-saves for your draft directory, but if
you do, ignore them at least in mu.

It may still trip up mbsync and friends, but not much we can do about
that.

Clean up the implementation a bit as well.
---
 lib/mu-scanner.cc | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/lib/mu-scanner.cc b/lib/mu-scanner.cc
index bbc8d7e6..7da9373f 100644
--- a/lib/mu-scanner.cc
+++ b/lib/mu-scanner.cc
@@ -98,21 +98,28 @@ ignore_dentry(const dentry_t& dentry)
 {
 	const auto d_name{dentry.d_name.c_str()};
 
-	/* dotdir? */
-	if (d_name[0] == '\0' || (d_name[1] == '\0' && d_name[0] == '.') ||
+	/* ignore '.' and '..' and anything starting with '#' (emacs
+	 * auto-saves) */
+	if (d_name[0] == '\0' || d_name[0] == '#' ||
+	    (d_name[1] == '\0' && d_name[0] == '.') ||
 	    (d_name[2] == '\0' && d_name[0] == '.' && d_name[1] == '.'))
 		return true;
 
-	if (d_name[0] != 't' && d_name[0] != 'h' && d_name[0] != '.')
-		return false; /* don't ignore */
-
-	if (::strcmp(d_name, "tmp") == 0 || ::strcmp(d_name, "hcache.db") == 0)
-		return true; // ignore
-
-	if (d_name[0] == '.')
-		for (auto dname : { "nnmaildir", "notmuch", "noindex", "noupdate"})
+	switch (d_name[0]) {
+	case 't':
+		if (::strcmp(d_name, "tmp") == 0)
+			return true; // ignore the tmp dir
+		break;
+	case 'h':
+		if (::strcmp(d_name, "hcache.db") == 0)
+			return true; // ignore mutt cache
+		break;
+	case '.':
+		for (const auto& dname : {"nnmaildir", "notmuch", "noindex", "noupdate"})
 			if (::strcmp(d_name + 1, dname) == 0)
-				return true;
+				return true; // ignore some known other furniture
+		break;
+	}
 
 	return false; /* don't ignore */
 }