fix: writestr() should do nothing when empty .po

https://github.com/sabotage-linux/gettext-tiny/issues/14.

At line:439, writestr() is called to write down those strings that
have not been wrote down in the main loop.

When po files are empty, nothing is wrote down, so d->plurals_count ==
0. Then, deleting 'invalid' codes in writestr() was executed wrongly.
-1 is not a valid index, qsort will segfault, of course.

To fix the bug, we check d->num[pe_msgid]>0, so it will do nothing when
the files are empty.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/msgfmt.c b/src/msgfmt.c
index 26e8c3e..d9db752 100644
--- a/src/msgfmt.c
+++ b/src/msgfmt.c
@@ -248,7 +248,10 @@ static inline void writemsg(struct callbackdata *d) {
 
 static inline void writestr(struct callbackdata *d, struct po_info *info) {
 	// msgid xx; msgstr ""; is widely happened, it's invalid
-	if(!d->pluralstr_count) {
+
+	// https://github.com/sabotage-linux/gettext-tiny/issues/1
+	// no invalid, when empty, check d->num[pe_msgid]
+	if(!d->pluralstr_count && d->num[pe_msgid] > 0) {
 		d->len[pe_msgid]-=d->msgidbuf1_len;
 		d->len[pe_msgid]-=d->msgidbuf2_len;
 		d->len[pe_plural]-=d->pluralbuf1_len;