vi: do not truncate file to zero length. closes bug 2944.

function                                             old     new   delta
file_write                                            98     104      +6

1 files changed, 6 insertions, 1 deletions

diff --git a/editors/vi.c b/editors/vi.c
index 454cfcee4..4e5a5ac4a 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -2437,11 +2437,16 @@ static int file_write(char * fn, char * first, char * last)
                 return -2;
         }
         charcnt = 0;
-        fd = open(fn, (O_WRONLY | O_CREAT | O_TRUNC), 0666);
+        /* By popular request we do not open file with O_TRUNC,
+         * but instead ftruncate() it _after_ successful write.
+         * Might reduce amount of data lost on power fail etc.
+         */
+        fd = open(fn, (O_WRONLY | O_CREAT), 0666);
         if (fd < 0)
                 return -1;
         cnt = last - first + 1;
         charcnt = full_write(fd, first, cnt);
+        ftruncate(fd, charcnt);
         if (charcnt == cnt) {
                 // good write
                 //file_modified = FALSE; // the file has not been modified