nano

commit b6a1583e8ebbdf65c6b80e773736c994e1639aa1
parent 48df800db314cc7f8d80240f94b4a4fc6c2f7648
Author: Benno Schulenberg <bensberg@telfort.nl>
Date:   Sun,  2 Feb 2020 11:36:01 +0100

tweaks: take just one shot at reading the lock file, and correct a type

Don't bother looping until the 1024 bytes are read.  Writing the lock
file takes just one shot too, and that is more important to get right.

Also, correct the type for the result of read(), so that -1 doesn't
get turned into a positive number, which would mean that any error
would get ignored.

Diffstat:
M
src/files.c
 | 
9
+++------

1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/src/files.c b/src/files.c
@@ -293,7 +293,7 @@ int do_lockfile(const char *filename, bool ask_the_user)
 		char *lockbuf, *question, *pidstring, *postedname, *promptstr;
 		static char lockprog[11], lockuser[17];
 		int lockfd, lockpid, room, choice;
-		size_t readamt = 0, readtot = 0;
+		ssize_t readamt;
 
 		if ((lockfd = open(lockfilename, O_RDONLY)) < 0) {
 			statusline(ALERT, _("Error opening lock file %s: %s"),
@@ -303,14 +303,11 @@ int do_lockfile(const char *filename, bool ask_the_user)
 
 		lockbuf = charalloc(LOCKSIZE);
 
-		do {
-			readamt = read(lockfd, &lockbuf[readtot], LOCKSIZE - readtot);
-			readtot += readamt;
-		} while (readamt > 0 && readtot < LOCKSIZE);
+		readamt = read(lockfd, lockbuf, LOCKSIZE);
 
 		close(lockfd);
 
-		if (readtot < LOCKSIZE || lockbuf[0] != 0x62 || lockbuf[1] != 0x30) {
+		if (readamt < LOCKSIZE || lockbuf[0] != 0x62 || lockbuf[1] != 0x30) {
 			statusline(ALERT, _("Bad lock file is ignored: %s"), lockfilename);
 			free(lockbuf);
 			goto free_the_name;