Fix compiler warning in back branches (9.6, 10).

macdice · macdice · commit 618d139f82d4 · 2021-02-16T13:17:07.000+13:00
Back-patch a tiny bit of commit fbb2e9a into 9.6 and 10, to silence an uninitialized variable warning from GCC 10.2. Seen on buildfarm member handfish, and my own development workflow where I like to use -Werror. Discussion: https://postgr.es/m/CA%2BhUKGJRcwvK86Uf5t-FrTekZjqHtpv3u%3D3MuBg8Zw8R933Mqg%40mail.gmail.com
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
@@ -9325,6 +9325,8 @@ RestoreGUCState(void *gucstate)
 		if (varsourcefile[0])
 			read_gucstate_binary(&srcptr, srcend,
 								 &varsourceline, sizeof(varsourceline));
+		else
+			varsourceline = 0;
 		read_gucstate_binary(&srcptr, srcend,
 							 &varsource, sizeof(varsource));
 		read_gucstate_binary(&srcptr, srcend,
