awk: next_input_file can return NULL, don't SEGV in this case.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 11 insertions, 9 deletions

diff --git a/editors/awk.c b/editors/awk.c
index 7685546e5..0918026d7 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);