hush: fix bug in interactive shell introduced yesterday

hush: fix `process subst` (2 bugs)
NB: will delete and re-add hush_test in order to change file modes

1 files changed, 46 insertions, 42 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 32cd65c72..04fb00dc7 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -317,10 +317,10 @@ typedef struct {
 /* I can almost use ordinary FILE *.  Is open_memstream() universally
  * available?  Where is it documented? */
 struct in_str {
-        union {
-                const char *p;
-                int cached_ch;
-        };
+        const char *p;
+        /* eof_flag=1: last char in ->p is really an EOF */
+        char eof_flag; /* meaningless if ->p == NULL */
+        char peek_buf[2];
 #if ENABLE_HUSH_INTERACTIVE
         int __promptme;
         int promptmode;
@@ -976,7 +976,7 @@ static int b_check_space(o_string *o, int len)
 
 static int b_addchr(o_string *o, int ch)
 {
-        debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
+        debug_printf("b_addchr: '%c' o->lengtt=%d o=%p\n", ch, o->length, o);
         if (b_check_space(o, 1))
                 return B_NOSPAC;
         o->data[o->length] = ch;
@@ -1079,12 +1079,13 @@ static const char* setup_prompt_string(int promptmode)
 static line_input_t *line_input_state;
 #endif
 
-static int get_user_input(struct in_str *i)
+static void get_user_input(struct in_str *i)
 {
         static char the_command[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
 
         int r;
         const char *prompt_str;
+
         prompt_str = setup_prompt_string(i->promptmode);
 #if ENABLE_FEATURE_EDITING
         /*
@@ -1094,15 +1095,19 @@ static int get_user_input(struct in_str *i)
          ** child processes (rob@sysgo.de)
          */
         r = read_line_input(prompt_str, the_command, BUFSIZ-1, line_input_state);
+        i->eof_flag = (r < 0);
+        if (i->eof_flag) { /* EOF/error detected */
+                the_command[0] = EOF; /* yes, it will be truncated, it's ok */
+                the_command[1] = '\0';
+        }
 #else
         fputs(prompt_str, stdout);
         fflush(stdout);
         the_command[0] = r = fgetc(i->file);
         /*the_command[1] = '\0'; - already is and never changed */
+        i->eof_flag = (r == EOF);
 #endif
-        fflush(stdout);
         i->p = the_command;
-        return r; /* < 0 == EOF. Not meaningful otherwise */
 }
 #endif  /* INTERACTIVE */
 
@@ -1112,33 +1117,30 @@ static int file_get(struct in_str *i)
 {
         int ch;
 
-        ch = 0;
         /* If there is data waiting, eat it up */
-        if (i->cached_ch) {
-                ch = i->cached_ch ^ 0x100;
-                if (ch != EOF)
-                        i->cached_ch = 0;
+        if (i->p && *i->p) {
+ take_cached:
+                ch = *i->p++;
+                if (i->eof_flag && !*i->p)
+                        ch = EOF;
         } else {
                 /* need to double check i->file because we might be doing something
                  * more complicated by now, like sourcing or substituting. */
 #if ENABLE_HUSH_INTERACTIVE
                 if (interactive_fd && i->__promptme && i->file == stdin) {
-                        while (!i->p || !(interactive_fd && i->p[0])) {
-                                if (get_user_input(i) < 0)
-                                        return EOF;
-                        }
+                        do {
+                                get_user_input(i);
+                        } while (!*i->p); /* need non-empty line */
                         i->promptmode = 2;
                         i->__promptme = 0;
-                        if (i->p && *i->p) {
-                                ch = *i->p++;
-                        }
+                        goto take_cached;
                 } else
 #endif
                 {
                         ch = fgetc(i->file);
                 }
-                debug_printf("file_get: got a %d\n", ch);
         }
+        debug_printf("file_get: got a '%c' %d\n", ch, ch);
 #if ENABLE_HUSH_INTERACTIVE
         if (ch == '\n')
                 i->__promptme = 1;
@@ -1152,12 +1154,17 @@ static int file_get(struct in_str *i)
 static int file_peek(struct in_str *i)
 {
         int ch;
-        if (i->cached_ch) {
-                return i->cached_ch ^ 0x100;
+        if (i->p && *i->p) {
+                if (i->eof_flag && !i->p[1])
+                        return EOF;
+                return *i->p;
         }
         ch = fgetc(i->file);
-        i->cached_ch = ch ^ 0x100; /* ^ 0x100 so that it is never 0 */
-        debug_printf("file_peek: got a %d '%c'\n", ch, ch);
+        i->eof_flag = (ch == EOF);
+        i->peek_buf[0] = ch;
+        i->peek_buf[1] = '\0';
+        i->p = i->peek_buf;
+        debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
         return ch;
 }
 
@@ -1182,6 +1189,7 @@ static void setup_string_in_str(struct in_str *i, const char *s)
         i->promptmode = 1;
 #endif
         i->p = s;
+        i->eof_flag = 0;
 }
 
 static void mark_open(int fd)
@@ -2846,11 +2854,12 @@ static FILE *generate_stream_from_list(struct pipe *head)
 static int process_command_subs(o_string *dest, struct p_context *ctx,
         struct in_str *input, const char *subst_end)
 {
-        int retcode;
+        int retcode, ch, eol_cnt;
         o_string result = NULL_O_STRING;
         struct p_context inner;
         FILE *p;
         struct in_str pipe_str;
+
         initialize_context(&inner);
 
         /* recursion to generate command */
@@ -2863,25 +2872,20 @@ static int process_command_subs(o_string *dest, struct p_context *ctx,
         p = generate_stream_from_list(inner.list_head);
         if (p == NULL) return 1;
         mark_open(fileno(p));
-// FIXME: need to flag pipe_str to somehow discard all trailing newlines.
-// Example: echo "TEST`date;echo;echo`BEST"
-//          must produce one line: TEST<date>BEST
         setup_file_in_str(&pipe_str, p);
 
         /* now send results of command back into original context */
-// FIXME: must not do quote parsing of the output!
-// Example: echo "TEST`echo '$(echo ZZ)'`BEST"
-//          must produce TEST$(echo ZZ)BEST, not TESTZZBEST.
-// Example: echo "TEST`echo "'"`BEST"
-//          must produce TEST'BEST
-// (maybe by setting all chars flagged as literals in map[]?)
-
-        retcode = parse_stream(dest, ctx, &pipe_str, NULL);
-        /* XXX In case of a syntax error, should we try to kill the child?
-         * That would be tough to do right, so just read until EOF. */
-        if (retcode == 1) {
-                while (b_getch(&pipe_str) != EOF)
-                        /* discard */;
+        eol_cnt = 0;
+        while ((ch = b_getch(&pipe_str)) != EOF) {
+                if (ch == '\n') {
+                        eol_cnt++;
+                        continue;
+                }
+                while (eol_cnt) {
+                        b_addqchr(dest, '\n', dest->quote);
+                        eol_cnt--;
+                }
+                b_addqchr(dest, ch, dest->quote);
         }
 
         debug_printf("done reading from pipe, pclose()ing\n");