commit b6c8e5e0edc57f309ae866114527e614ad0cd76d
from: Stefan Sperling <stsp@stsp.name>
via: Thomas Adam <thomas@xteddy.org>
date: Tue Oct 12 20:02:46 2021 UTC

fix a segfault in edscript() introduced by my previous commit

Found by our cherrypick regression tests.

commit - 461f6aedbd48fa1a352a579c70013ff02d50a6c5
commit + b6c8e5e0edc57f309ae866114527e614ad0cd76d
blob - cdb83d926a830340f0bdbf339072f2e5f816d3be
blob + 899e70b054294423e8273fb0e275949925cc8909
--- lib/diff3.c
+++ lib/diff3.c
@@ -981,7 +981,7 @@ edscript(int n, struct diff3_state *d3s)
 	off_t len;
 	char *line = NULL;
 	size_t linesize = 0;
-	ssize_t linelen, k;
+	ssize_t linelen = 0, k;
 
 	for (; n > 0; n--) {
 		if (!d3s->overlap[n]) {
@@ -1012,7 +1012,7 @@ edscript(int n, struct diff3_state *d3s)
 					goto done;
 			}
 			err = diff_output(d3s->diffbuf, "%s%s\n",
-			    line[linelen] == '\n' ? ":" : "",
+			    linelen > 0 && line[linelen] == '\n' ? ":" : "",
 			    GOT_DIFF_CONFLICT_MARKER_SEP);
 			if (err)
 				goto done;