Navit crashes if destination.txt cannot be written

[sleske]

If destination.txt cannot be written to (for example because of filesystem permissions), Navit will segfault as soon as it tries to write to it.

To reproduce (on Linux):

• set destination.txt read-only: chmod a-w path/to/destination.txt
• start Navit
• set a destination (by choosing a bookmark, or entering it directly)

Navit will segfault. Backtrace (shortened):

[...]
#4  0x08062ecf in sigsegv (sig=11) at debug.c:80
#5  <signal handler called>
#6  0xb7463e47 in fclose () from /lib/i386-linux-gnu/i686/cmov/libc.so.6
#7  0x08093074 in bookmarks_append_coord at bookmarks.c:704
#8  0x080731ff in navit_set_destination  at navit.c:1483
[...]

[sleske]

Fix for issue #959: Do not call fclose() if fopen() failed

[sleske]

The cause of this crash is that Navit tries to close the file handle for destination.txt, even if the fopen() call failed (in bookmarks.c, function bookmarks_append_coord).

I attached a patch to fix this.

[number6]

This patch uses dbg to notify the user, and stops the program from crashing

[number6]

Added my own ​patch in ​Revision 4845!

[sleske]

Hm, to be honest, I believe my patch is a bit better (because it prints the cause of the error). Anyway, the main thing is that it's fixed.