From 431cdfd983bc9864d6a44a456a97b72455bb17cd Mon Sep 17 00:00:00 2001
From: Pino Toscano <ptoscano@redhat.com>
Date: Mon, 1 Sep 2014 11:46:57 +0200
Subject: [PATCH] fish: edit: write to the real file name

When saving, resolve the path of the file being edited and use that as
real target to write to. Otherwise, if the file name is a symlink then
it will be replaced by a regular file with the new content, leaving the
old file untouched.

Extend test-edit.sh to check for this situation.
---
 fish/file-edit.c  | 15 ++++++++++++++-
 fish/test-edit.sh | 12 +++++++++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/fish/file-edit.c b/fish/file-edit.c
index e6d25f5ab..dd2272bba 100644
--- a/fish/file-edit.c
+++ b/fish/file-edit.c
@@ -216,11 +216,24 @@ do_download (guestfs_h *g, const char *filename, char **tempfile)
 }
 
 static int
-do_upload (guestfs_h *g, const char *filename, const char *tempfile,
+do_upload (guestfs_h *g, const char *fn, const char *tempfile,
            const char *backup_extension)
 {
+  CLEANUP_FREE char *filename = NULL;
   CLEANUP_FREE char *newname = NULL;
 
+  /* Resolve the file name and write to the actual target, since
+   * that is the file it was opened earlier; otherwise, if it is
+   * a symlink it will be overwritten by a regular file with the
+   * new content.
+   *
+   * Theoretically realpath should work, but just check again
+   * to be safe.
+   */
+  filename = guestfs_realpath (g, fn);
+  if (filename == NULL)
+    return -1;
+
   /* Upload to a new file in the same directory, so if it fails we
    * don't end up with a partially written file.  Give the new file
    * a completely random name so we have only a tiny chance of
diff --git a/fish/test-edit.sh b/fish/test-edit.sh
index 34bfc9dc3..9d7ab9d7b 100755
--- a/fish/test-edit.sh
+++ b/fish/test-edit.sh
@@ -43,6 +43,12 @@ cat /file.txt
 stat /file.txt | grep mode:
 stat /file.txt | grep uid:
 stat /file.txt | grep gid:
+echo ==========
+write /file-2.txt "symlink test\n"
+ln-s /file-2.txt /symlink-2.txt
+edit /symlink-2.txt
+is-symlink /symlink-2.txt
+cat /symlink-2.txt
 EOF
 )
 
@@ -51,7 +57,11 @@ second line of text
 
 mode: 33152
 uid: 10
-gid: 11" ]; then
+gid: 11
+==========
+true
+symlink test
+second line of text" ]; then
     echo "$0: error: output of guestfish after edit command did not match expected output"
     echo "$output"
     exit 1