nano/0001-check-stat-s-result-and-avoid-calling-stat-on-a-NULL.patch
2014-05-29 10:04:02 +02:00

81 lines
2.8 KiB
Diff

From fc87b0a32c130a2b3ab37e614d4a1c6c8e5d70e7 Mon Sep 17 00:00:00 2001
From: Kamil Dudka <kdudka@redhat.com>
Date: Thu, 19 Aug 2010 13:58:12 +0200
Subject: [PATCH 2/3] check stat's result and avoid calling stat on a NULL pointer
---
src/files.c | 36 +++++++++++++++++++++++++-----------
1 file changed, 25 insertions(+), 11 deletions(-)
diff --git a/src/files.c b/src/files.c
index f6efbf1..99cc1b8 100644
--- a/src/files.c
+++ b/src/files.c
@@ -300,6 +300,24 @@ int do_lockfile(const char *filename)
}
#endif /* !NANO_TINY */
+#ifndef NANO_TINY
+/* If *pstat is NULL, perform a stat call with the given file name. On success,
+ * *pstat points to a newly allocated buffer that contains the stat's result.
+ * On stat's failure, the NULL pointer in *pstat is left intact. */
+void stat_if_needed(const char *filename, struct stat **pstat)
+{
+ struct stat *tmp;
+ if (*pstat)
+ return;
+
+ tmp = (struct stat *)nmalloc(sizeof(struct stat));
+ if (0 == stat(filename, tmp))
+ *pstat = tmp;
+ else
+ free(tmp);
+}
+#endif
+
/* If it's not "", filename is a file to open. We make a new buffer, if
* necessary, and then open and read the file, if applicable. */
void open_buffer(const char *filename, bool undoable)
@@ -345,11 +363,7 @@ void open_buffer(const char *filename, bool undoable)
if (rc > 0) {
read_file(f, rc, filename, undoable, new_buffer);
#ifndef NANO_TINY
- if (openfile->current_stat == NULL) {
- openfile->current_stat =
- (struct stat *)nmalloc(sizeof(struct stat));
- stat(filename, openfile->current_stat);
- }
+ stat_if_needed(filename, &openfile->current_stat);
#endif
}
@@ -1737,10 +1751,8 @@ bool write_file(const char *name, FILE *f_open, bool tmp, append_type
* specified it interactively), stat and save the value now,
* or else we will chase null pointers when we do modtime checks,
* preserve file times, and so on, during backup. */
- if (openfile->current_stat == NULL && !tmp && realexists) {
- openfile->current_stat = (struct stat *)nmalloc(sizeof(struct stat));
- stat(realname, openfile->current_stat);
- }
+ if (!tmp && realexists)
+ stat_if_needed(realname, &openfile->current_stat);
/* We backup only if the backup toggle is set, the file isn't
* temporary, and the file already exists. Furthermore, if we
@@ -2133,8 +2145,10 @@ bool write_file(const char *name, FILE *f_open, bool tmp, append_type
if (openfile->current_stat == NULL)
openfile->current_stat =
(struct stat *)nmalloc(sizeof(struct stat));
- if (!openfile->mark_set)
- stat(realname, openfile->current_stat);
+ if (!openfile->mark_set && 0 != stat(realname, openfile->current_stat)) {
+ free(openfile->current_stat);
+ openfile->current_stat = NULL;
+ }
#endif
statusbar(P_("Wrote %lu line", "Wrote %lu lines",
--
1.7.4