cmd/libsnap: fix cleanup and error compatiblity

Some variables have automatic cleanup handlers. Some other variables need special paired function calls (va_start, va_end). This makes is more challenging to use "goto out" error handling strategy. Fix the mistakes I made earlier. Signed-off-by: Zygmunt Krynicki <me@zygoon.pl> 

1 files changed, 6 insertions, 5 deletions

diff --git a/cmd/libsnap-confine-private/infofile.c b/cmd/libsnap-confine-private/infofile.c
index 45e9d994d0..eb2e850562 100644
--- a/cmd/libsnap-confine-private/infofile.c
+++ b/cmd/libsnap-confine-private/infofile.c
@@ -30,6 +30,8 @@ int sc_infofile_query(FILE *stream, sc_error **err_out, ...) {
 va_list ap;
 va_start(ap, err_out);
 sc_error *err = NULL;
+ size_t line_size = 0;
+ char *line_buf SC_CLEANUP(sc_cleanup_string) = NULL;
 
 fpos_t start_pos;
 if (fgetpos(stream, &start_pos) < 0) {
@@ -37,8 +39,6 @@ int sc_infofile_query(FILE *stream, sc_error **err_out, ...) {
 goto out;
 }
 
- size_t line_size = 0;
- char *line_buf SC_CLEANUP(sc_cleanup_string) = NULL;
 for (;;) { /* This loop advances through the keys we are looking for. */
 const char *key = va_arg(ap, const char *);
 if (key == NULL) {
@@ -65,6 +65,8 @@ int sc_infofile_query(FILE *stream, sc_error **err_out, ...) {
 if (nread <= 0) {
 break; /* There is nothing more to read. */
 }
+ /* NOTE: beyond this line the buffer is never empty. */
+
 /* Guard against malformed input that may contain NUL bytes that
 * would confuse the code below. */
 if (memchr(line_buf, '\0', nread) != NULL) {
@@ -85,7 +87,7 @@ int sc_infofile_query(FILE *stream, sc_error **err_out, ...) {
 continue;
 }
 /* Replace the newline character, if any, with the NUL byte. */
- if (nread > 0 && line_buf[nread - 1] == '\n') {
+ if (line_buf[nread - 1] == '\n') {
 line_buf[nread - 1] = '\0';
 nread--;
 }
@@ -98,13 +100,12 @@ int sc_infofile_query(FILE *stream, sc_error **err_out, ...) {
 }
 }
 }
- va_end(ap);
 if (fsetpos(stream, &start_pos) < 0) {
 err = sc_error_init_from_errno(errno, "cannot set stream position");
 goto out;
 }
-
 out:
+ va_end(ap);
 sc_error_forward(err_out, err);
 return err != NULL ? -1 : 0;
 }