awk: unbreak "printf('%c') can output NUL" testcase

function                                             old     new   delta
awk_printf                                           546     593     +47

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

1 files changed, 26 insertions, 17 deletions

diff --git a/editors/awk.c b/editors/awk.c
index 0aa7c0804..e765d3fcf 100644
--- a/editors/awk.c
+++ b/editors/awk.c
@@ -2309,11 +2309,11 @@ static int awk_getline(rstream *rsm, var *v)
 #if !ENABLE_FEATURE_AWK_GNU_EXTENSIONS
 # define awk_printf(a, b) awk_printf(a)
 #endif
-static char *awk_printf(node *n, int *len)
+static char *awk_printf(node *n, size_t *len)
 {
         char *b;
         char *fmt, *f;
-        int i;
+        size_t i;
 
         //tmpvar = nvalloc(1);
 #define TMPVAR (&G.awk_printf__tmpvar)
@@ -2333,6 +2333,7 @@ static char *awk_printf(node *n, int *len)
                 char c;
                 char sv;
                 var *arg;
+                size_t slen;
 
                 s = f;
                 while (*f && (*f != '%' || *++f == '%'))
@@ -2347,6 +2348,7 @@ static char *awk_printf(node *n, int *len)
                         /* Tail of fmt with no percent chars,
                          * or "....%" (percent seen, but no format specifier char found)
                          */
+                        slen = strlen(s);
                         goto tail;
                 }
                 sv = *++f;
@@ -2357,31 +2359,38 @@ static char *awk_printf(node *n, int *len)
                  *  printf "%99999s", "BOOM"
                  */
                 if (c == 'c') {
-                        s = xasprintf(s, is_numeric(arg) ?
-                                        (char)getvar_i(arg) : *getvar_s(arg));
-                } else if (c == 's') {
-                        s = xasprintf(s, getvar_s(arg));
+                        c = is_numeric(arg) ? getvar_i(arg) : *getvar_s(arg);
+                        s = xasprintf(s, c);
+                        /* + 1 if c == NUL: handle printf "%c" 0 case
+                         * (and printf "%22c" 0 etc, but still fails for e.g. printf "%-22c" 0) */
+                        slen = strlen(s) + (c == '\0');
                 } else {
-                        double d = getvar_i(arg);
-                        if (strchr("diouxX", c)) {
-//TODO: make it wider here (%x -> %llx etc)?
-                                s = xasprintf(s, (int)d);
-                        } else if (strchr("eEfFgGaA", c)) {
-                                s = xasprintf(s, d);
+                        if (c == 's') {
+                                s = xasprintf(s, getvar_s(arg));
                         } else {
-                                syntax_error(EMSG_INV_FMT);
+                                double d = getvar_i(arg);
+                                if (strchr("diouxX", c)) {
+//TODO: make it wider here (%x -> %llx etc)?
+                                        s = xasprintf(s, (int)d);
+                                } else if (strchr("eEfFgGaA", c)) {
+                                        s = xasprintf(s, d);
+                                } else {
+                                        syntax_error(EMSG_INV_FMT);
+                                }
                         }
+                        slen = strlen(s);
                 }
                 *f = sv;
 
                 if (i == 0) {
                         b = s;
-                        i = strlen(b);
+                        i = slen;
                         continue;
                 }
  tail:
-                b = xrealloc(b, i + strlen(s) + 1);
-                i = stpcpy(b + i, s) - b;
+                b = xrealloc(b, i + slen + 1);
+                strcpy(b + i, s);
+                i += slen;
                 if (!c) /* tail? */
                         break;
                 free(s);
@@ -2926,7 +2935,6 @@ static var *evaluate(node *op, var *res)
                         debug_printf_eval("PRINTF\n");
                 {
                         FILE *F = stdout;
-                        IF_FEATURE_AWK_GNU_EXTENSIONS(int len;)
 
                         if (op->r.n) {
                                 rstream *rsm = newfile(R.s);
@@ -2966,6 +2974,7 @@ static var *evaluate(node *op, var *res)
                                 }
                                 fputs(getvar_s(intvar[ORS]), F);
                         } else {        /* PRINTF */
+                                IF_FEATURE_AWK_GNU_EXTENSIONS(size_t len;)
                                 char *s = awk_printf(op1, &len);
 #if ENABLE_FEATURE_AWK_GNU_EXTENSIONS
                                 fwrite(s, len, 1, F);