[git commit] awk: next_input_file can return NULL, don't SEGV in this case.

[Denys Vlasenko]

commit: http://git.busybox.net/busybox/commit/?id=f65c5f5c547c48b7766db58d10043a504d953aa1
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 editors/awk.c |   20 +++++++++++---------
 1 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/editors/awk.c b/editors/awk.c
index 7685546..0918026 100644
--- a/editors/awk.c
+++ b/editors/awk.c
@@ -2627,7 +2627,7 @@ static var *evaluate(node *op, var *res)
 				rsm = iF;
 			}
 
-			if (!rsm->F) {
+			if (!rsm || !rsm->F) {
 				setvar_i(intvar[ERRNO], errno);
 				setvar_i(res, -1);
 				break;
@@ -2961,7 +2961,7 @@ static rstream *next_input_file(void)
 #define rsm          (G.next_input_file__rsm)
 #define files_happen (G.next_input_file__files_happen)
 
-	FILE *F = NULL;
+	FILE *F;
 	const char *fname, *ind;
 
 	if (rsm.F)
@@ -2969,19 +2969,21 @@ static rstream *next_input_file(void)
 	rsm.F = NULL;
 	rsm.pos = rsm.adv = 0;
 
-	do {
+	for (;;) {
 		if (getvar_i(intvar[ARGIND])+1 >= getvar_i(intvar[ARGC])) {
 			if (files_happen)
 				return NULL;
 			fname = "-";
 			F = stdin;
-		} else {
-			ind = getvar_s(incvar(intvar[ARGIND]));
-			fname = getvar_s(findvar(iamarray(intvar[ARGV]), ind));
-			if (fname && *fname && !is_assignment(fname))
-				F = xfopen_stdin(fname);
+			break;
 		}
-	} while (!F);
+		ind = getvar_s(incvar(intvar[ARGIND]));
+		fname = getvar_s(findvar(iamarray(intvar[ARGV]), ind));
+		if (fname && *fname && !is_assignment(fname)) {
+			F = xfopen_stdin(fname);
+			break;
+		}
+	}
 
 	files_happen = TRUE;
 	setvar_s(intvar[FILENAME], fname);
-- 
1.7.3.4