bc: fix EOF handling in bc_program_read()

$ bc -q
read()
2^D^D2
     ^ prints the result of read()'ed expression

function                                             old     new   delta
zbc_program_print                                    629     642     +13
bc_program_read                                      322     312     -10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 13/-10)              Total: 3 bytes

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

1 files changed, 11 insertions, 9 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 143bb64b1..32e002913 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -1358,6 +1358,8 @@ static int push_input_byte(BcVec *vec, char c)
 }
 
 // This is not a "z" function: can also return BC_STATUS_EOF
+// Can return success (0) or BC_STATUS_EOF.
+// Exits with error message if read error is detected.
 static BcStatus bc_read_line(BcVec *vec)
 {
         BcStatus s;
@@ -5523,7 +5525,7 @@ static BcStatus bc_program_read(void)
         G.prog.file = NULL;
 
         s = bc_read_line(&buf);
-        if (s) goto io_err;
+        //if (s) goto io_err; - wrong, nonzero return means EOF, not error
 
         common_parse_init(&parse, BC_PROG_READ);
         bc_lex_file(&parse.l);
@@ -5549,9 +5551,9 @@ static BcStatus bc_program_read(void)
         bc_vec_push(&G.prog.stack, &ip);
 
 exec_err:
-        G.prog.file = sv_file;
         bc_parse_free(&parse);
-io_err:
+//io_err:
+        G.prog.file = sv_file;
         bc_vec_free(&buf);
         return s;
 }
@@ -7171,8 +7173,8 @@ static BcStatus bc_vm_stdin(void)
 {
         BcStatus s;
         BcVec buf, buffer;
-        size_t len, i, str = 0;
-        bool comment = false;
+        size_t str;
+        bool comment;
 
         G.prog.file = NULL;
         bc_lex_file(&G.prs.l);
@@ -7185,12 +7187,13 @@ static BcStatus bc_vm_stdin(void)
         // with a backslash to the parser. The reason for that is because the parser
         // treats a backslash+newline combo as whitespace, per the bc spec. In that
         // case, and for strings and comments, the parser will expect more stuff.
+        comment = false;
+        str = 0;
         while ((s = bc_read_line(&buf)) == BC_STATUS_SUCCESS) {
-
+                size_t len;
                 char *string = buf.v;
 
                 len = buf.len - 1;
-
                 if (len == 1) {
                         if (str && buf.v[0] == G.send)
                                 str -= 1;
@@ -7198,9 +7201,8 @@ static BcStatus bc_vm_stdin(void)
                                 str += 1;
                 }
                 else if (len > 1 || comment) {
-
+                        size_t i;
                         for (i = 0; i < len; ++i) {
-
                                 bool notend = len > i + 1;
                                 char c = string[i];