awk: fix a case with multiple -f options. simplify -f file reading.

function                                             old     new   delta
parse_expr                                           833     841      +8
qrealloc                                              33      36      +3
next_input_file                                      203     198      -5
afopen                                                22       -     -22
ftello                                                41       -     -41
ftell                                                 41       -     -41
__GI_ftell                                            41       -     -41
awk_main                                            1002     944     -58
------------------------------------------------------------------------------
(add/remove: 0/4 grow/shrink: 2/2 up/down: 11/-208)          Total: -197 bytes
   text    data     bss     dec     hex filename
 804232     610    6804  811646   c627e busybox_old
 804120     610    6804  811534   c620e busybox_unstripped

3 files changed, 28 insertions, 27 deletions

diff --git a/editors/awk.c b/editors/awk.c
index fef3246b8..cc5dc84b5 100644
--- a/editors/awk.c
+++ b/editors/awk.c
@@ -681,11 +681,6 @@ static ALWAYS_INLINE int isalnum_(int c)
 	return (isalnum(c) || c == '_');
 }
 
-static FILE *afopen(const char *path, const char *mode)
-{
-	return (*path == '-' && *(path+1) == '\0') ? stdin : xfopen(path, mode);
-}
-
 /* -------- working with variables (set/get/copy/etc) -------- */
 
 static xhash *iamarray(var *v)
@@ -2740,7 +2735,7 @@ static rstream *next_input_file(void)
 			ind = getvar_s(incvar(intvar[ARGIND]));
 			fname = getvar_s(findvar(iamarray(intvar[ARGV]), ind));
 			if (fname && *fname && !is_assignment(fname))
-				F = afopen(fname, "r");
+				F = xfopen_stdin(fname);
 		}
 	} while (!F);
 
@@ -2757,8 +2752,9 @@ int awk_main(int argc, char **argv)
 {
 	unsigned opt;
 	char *opt_F, *opt_W;
-	llist_t *opt_v = NULL;
-	int i, j, flen;
+	llist_t *list_v = NULL;
+	llist_t *list_f = NULL;
+	int i, j;
 	var *v;
 	var tv;
 	char **envp;
@@ -2816,35 +2812,33 @@ int awk_main(int argc, char **argv)
 			*s1 = '=';
 		}
 	}
-	opt_complementary = "v::";
-	opt = getopt32(argv, "F:v:f:W:", &opt_F, &opt_v, &g_progname, &opt_W);
+	opt_complementary = "v::f::"; /* -v and -f can occur multiple times */
+	opt = getopt32(argv, "F:v:f:W:", &opt_F, &list_v, &list_f, &opt_W);
 	argv += optind;
 	argc -= optind;
 	if (opt & 0x1)
 		setvar_s(intvar[FS], opt_F); // -F
-	while (opt_v) { /* -v */
-		if (!is_assignment(llist_pop(&opt_v)))
+	while (list_v) { /* -v */
+		if (!is_assignment(llist_pop(&list_v)))
 			bb_show_usage();
 	}
-	if (opt & 0x4) { // -f
-		char *s = s; /* die, gcc, die */
-		FILE *from_file = afopen(g_progname, "r");
-		/* one byte is reserved for some trick in next_token */
-		if (fseek(from_file, 0, SEEK_END) == 0) {
-			flen = ftell(from_file);
-			s = xmalloc(flen + 4);
-			fseek(from_file, 0, SEEK_SET);
-			i = 1 + fread(s + 1, 1, flen, from_file);
-		} else {
+	if (list_f) { /* -f */
+		do {
+			char *s = NULL;
+			FILE *from_file;
+
+			g_progname = llist_pop(&list_f);
+			from_file = xfopen_stdin(g_progname);
+			/* one byte is reserved for some trick in next_token */
 			for (i = j = 1; j > 0; i += j) {
 				s = xrealloc(s, i + 4096);
 				j = fread(s + i, 1, 4094, from_file);
 			}
-		}
-		s[i] = '\0';
-		fclose(from_file);
-		parse_program(s + 1);
-		free(s);
+			s[i] = '\0';
+			fclose(from_file);
+			parse_program(s + 1);
+			free(s);
+		} while (list_f);
 	} else { // no -f: take program from 1st parameter
 		if (!argc)
 			bb_show_usage();
diff --git a/testsuite/awk.tests b/testsuite/awk.tests
index 91657418d..f69da2cc9 100755
--- a/testsuite/awk.tests
+++ b/testsuite/awk.tests
@@ -17,4 +17,11 @@ testing "awk -F case 5" "awk -F '[#]' '{ print NF }'" "4\n" "" "#abc##zz\n"
 testing "awk -F case 6" "awk -F '[#]' '{ print NF }'" "4\n" "" "z#abc##zz\n"
 testing "awk -F case 7" "awk -F '[#]' '{ print NF }'" "5\n" "" "z##abc##zz\n"
 
+tar xjf awk_t1.tar.bz2
+testing "awk 'gcc build bug'" \
+	"awk -f awk_t1_opt-functions.awk -f awk_t1_opth-gen.awk <awk_t1_input | md5sum" \
+	"f842e256461a5ab1ec60b58d16f1114f  -\n" \
+	"" ""
+rm -rf awk_t1_*
+
 exit $FAILCOUNT
diff --git a/testsuite/awk_t1.tar.bz2 b/testsuite/awk_t1.tar.bz2
new file mode 100644
index 000000000..0fb8a0743
--- /dev/null
+++ b/testsuite/awk_t1.tar.bz2