From a1eafa7c48fb08f96613e85ad6ee3af5532bf2f3 Mon Sep 17 00:00:00 2001
From: Philipp Takacs <philipp@bureaucracy.de>
Date: Thu, 19 Mar 2020 02:50:51 +0100
Subject: [PATCH] use scandir in folder_read

---
 sbr/folder_read.c |  149 ++++++++++++++++++++---------------------------------
 1 file changed, 56 insertions(+), 93 deletions(-)

diff --git a/sbr/folder_read.c b/sbr/folder_read.c
index 011958f..6a8139a 100644
--- a/sbr/folder_read.c
+++ b/sbr/folder_read.c
@@ -12,9 +12,6 @@
 #include <dirent.h>
 #include <sys/stat.h>
 
-/* We allocate the `mi' array 1024 elements at a time */
-#define NUMMSGS  1024
-
 /*
 ** 1) Create the folder/message structure
 ** 2) Read the directory (folder) and temporarily
@@ -24,121 +21,87 @@
 ** 4) Read and initialize the sequence information.
 */
 
+static int others;
+
+static int
+msgnumcmp(const struct dirent **d1, const struct dirent **d2)
+{
+	size_t l1, l2;
+
+	l1 = strlen((*d1)->d_name);
+	l2 = strlen((*d2)->d_name);
+	if (l1 < l2) {
+		return -1;
+	}
+	if (l1 > l2) {
+		return 1;
+	}
+	return strcmp((*d1)->d_name, (*d2)->d_name);
+}
+
+static int
+msgfilter(const struct dirent *e)
+{
+	int i;
+	/* For compatibility with nmh, ignore rmm backup files. */
+	if (e->d_name[0] == '.' || e->d_name[0] == ',' || e->d_name[0] == '#') {
+		return 0;
+	}
+	for (i = 0; e->d_name[i]; i++) {
+		if ((i == 0 && e->d_name[i] == '0') || e->d_name[i] < '0' || e->d_name[i] > '9') {
+			others = 1;
+			return 0;
+		}
+	}
+	return 1;
+}
+
 struct msgs *
 folder_read(char *name)
 {
-	int msgnum, len, *mi;
+	int i;
 	struct msgs *mp;
 	struct stat st;
-	struct dirent *dp;
-	DIR *dd;
+	struct dirent **dp;
 
+	others = 0;
 	name = mh_xstrdup(toabsdir(name));
-	if (!(dd = opendir(name))) {
-		mh_free0(&name);
-		return NULL;
-	}
 
 	if (stat(name, &st) == -1) {
 		mh_free0(&name);
-		closedir(dd);
 		return NULL;
 	}
 
 	/* Allocate the main structure for folder information */
 	mp = mh_xcalloc(1, sizeof(*mp));
 
-	clear_folder_flags(mp);
 	mp->foldpath = name;
-	mp->lowmsg = 0;
-	mp->hghmsg = 0;
-	mp->curmsg = 0;
-	mp->lowsel = 0;
-	mp->hghsel = 0;
-	mp->numsel = 0;
-	mp->nummsg = 0;
 
 	if (access(name, W_OK) == -1)
 		set_readonly(mp);
 
-	/*
-	** Allocate a temporary place to record the
-	** name of the messages in this folder.
-	*/
-	len = NUMMSGS;
-	mi = mh_xcalloc(len, sizeof(*mi));
-
-	while ((dp = readdir(dd))) {
-		if ((msgnum = m_atoi(dp->d_name)) && msgnum > 0) {
-			/*
-			** Check if we need to allocate more
-			** temporary elements for message names.
-			*/
-			if (mp->nummsg >= len) {
-				len += NUMMSGS;
-				mi = mh_xrealloc(mi, len * sizeof(*mi));
-			}
-
-			/* Check if this is the first message we've seen */
-			if (mp->nummsg == 0) {
-				mp->lowmsg = msgnum;
-				mp->hghmsg = msgnum;
-			} else {
-				/*
-				** Check if this is it the highest or
-				** lowest we've seen?
-				*/
-				if (msgnum < mp->lowmsg)
-					mp->lowmsg = msgnum;
-				if (msgnum > mp->hghmsg)
-					mp->hghmsg = msgnum;
-			}
-
-			/*
-			** Now increment count, and record message
-			** number in a temporary place for now.
-			*/
-			mi[mp->nummsg++] = msgnum;
-
-		} else {
-			switch (dp->d_name[0]) {
-			case '.':
-			case ',':
-				continue;
-
-			default:
-				/*
-				** indicate that there are other
-				** files in folder
-				*/
-				set_other_files(mp);
-				continue;
-			}
-		}
-	}
+	mp->nummsg = scandir(name, &dp, msgfilter, msgnumcmp);
 
-	closedir(dd);
-	mp->lowoff = max(mp->lowmsg, 1);
+	if (others)
+		set_other_files(mp);
 
-	/* Go ahead and allocate space for 100 additional messages. */
+	if (mp->nummsg < 0) {
+		mh_free0(&name);
+		mh_free0(&mp);
+		return NULL;
+	}
+	if (mp->nummsg > 0) {
+		mp->lowmsg = m_atoi(dp[0]->d_name);
+		mp->hghmsg = m_atoi(dp[mp->nummsg-1]->d_name);
+	}
+	mp->lowoff = max(mp->lowmsg, 1);
 	mp->hghoff = mp->hghmsg + 100;
-
-	/* for testing, allocate minimal necessary space */
-	/* mp->hghoff = max(mp->hghmsg, 1); */
-
-	/* Allocate space for status of each message. */
-
 	mp->msgstats = mh_xcalloc(MSGSTATSIZE(mp, mp->lowoff, mp->hghoff), 1);
-
-	/*
-	** Scan through the array of messages we've seen and
-	** setup the initial flags for those messages in the
-	** newly allocated mp->msgstats area.
-	*/
-	for (msgnum = 0; msgnum < mp->nummsg; msgnum++)
-		set_exists(mp, mi[msgnum]);
-
-	mh_free0(&mi);  /* We don't need this anymore */
+	for (i = 0; i < mp->nummsg; i++) {
+		set_exists(mp, m_atoi(dp[i]->d_name));
+		mh_free0(dp + i);
+	}
+	mh_free0(&dp);
 
 	/*
 	** Read and initialize the sequence information.
-- 
1.7.10.4