pam_env: _parse_line: fix quoteflg handled

Check if quote flag is positive before decrementing it. Otherwise, for
some use case, it could become negative, and have an unwanted empty string
instead of an undefined variable.

Signed-off-by: Valentin Lefebvre <valentin.lefebvre@suse.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/modules/pam_env/pam_env.c b/modules/pam_env/pam_env.c
index 66fbe240..64a58645 100644
--- a/modules/pam_env/pam_env.c
+++ b/modules/pam_env/pam_env.c
@@ -293,7 +293,8 @@ _parse_line(const pam_handle_t *pamh, const char *buffer, VAR *var)
       }
       (void)strncpy(*valptr,ptr,length);
       (*valptr)[length]='\0';
-    } else if (quoteflg--) {
+    } else if (quoteflg) {
+      quoteflg--;
       *valptr = &quote;      /* a quick hack to handle the empty string */
     }
     ptr = tmpptr;         /* Start the search where we stopped */