Perl_sv_vcatpvfn_flags: simplify an expression

[perl5.git] / sv.c

diff --git a/sv.c b/sv.c
index 8c79581..f56fc16 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -11444,6 +11444,12 @@ S_hextract(pTHX_ const NV nv, int* exponent, bool *subnormal,
     } STMT_END
 
 void
+
+
+/* This function assumes that pat has the same utf8-ness as sv.
+ * It's the caller's responsibility to ensure that this is so.
+ */
+
 Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN patlen,
                        va_list *const args, SV **const svargs, const I32 svmax, bool *const maybe_tainted,
                        const U32 flags)
@@ -11628,7 +11634,6 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
 #endif
         NV nv;
        STRLEN float_need; /* what PL_efloatsize needs to become */
-       STRLEN gap;
        const char *dotstr = ".";
        STRLEN dotstrlen = 1;
        I32 efix = 0; /* explicit format parameter index */
@@ -12688,7 +12693,7 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
 
                     if (has_precis) {
                         U8* ve = (subnormal ? vlnz + 1 : vend);
-                        SSize_t vn = ve - (subnormal ? vfnz : vhex);
+                        SSize_t vn = ve - v0;
                         if ((SSize_t)(precis + 1) < vn) {
                             bool overflow = FALSE;
                             if (v0[precis + 1] < 0x8) {
@@ -13004,19 +13009,10 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
                Perl_warner(aTHX_ packWARN(WARN_PRINTF), "%" SVf, SVfARG(msg)); /* yes, this is reentrant */
            }
 
-           /* output mangled stuff ... */
-           if (c == '\0')
-               --q;
-           eptr = p;
-           elen = q - p;
-
-           /* ... right here, because formatting flags should not apply */
-           SvGROW(sv, SvCUR(sv) + elen + 1);
-           p = SvEND(sv);
-           Copy(eptr, p, elen, char);
-           p += elen;
-           *p = '\0';
-           SvCUR_set(sv, p - SvPVX_const(sv));
+           /* mangled format: output the '%', then continue from the
+             * character following that */
+            sv_catpvn_nomg(sv, p, 1);
+            q = p + 1;
            svix = osvix;
            continue;   /* not "break" */
        }
@@ -13041,22 +13037,43 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
        }
 
 
+        /* append esignbuf, filler, zeros, eptr and dotstr to sv */
+
         {
-            STRLEN need, have;
+            STRLEN need, have, gap;
 
             /* signed value that's wrapped? */
             assert(elen  <= ((~(STRLEN)0) >> 1));
-            have = esignlen + zeros + elen;
-            if (have < zeros)
+
+            /* Most of these length vars can range to any value if
+             * supplied with a hostile format and/or args. So check every
+             * addition for possible overflow. In reality some of these
+             * values are interdependent so these checks are slightly
+             * redundant. But its easier to be certain this way.
+             */
+
+            have = elen;
+
+            if (have >= (((STRLEN)~0) - zeros))
                 croak_memory_wrap();
+            have += zeros;
+
+            if (have >= (((STRLEN)~0) - esignlen))
+                croak_memory_wrap();
+            have += esignlen;
 
             need = (have > width ? have : width);
             gap = need - have;
 
-            if (need >= (((STRLEN)~0) - SvCUR(sv) - dotstrlen - 1))
+            if (need >= (((STRLEN)~0) - dotstrlen))
                 croak_memory_wrap();
-            SvGROW(sv, SvCUR(sv) + need + dotstrlen + 1);
-        }
+            need += dotstrlen;
+
+            if (need >= (((STRLEN)~0) - (SvCUR(sv) + 1)))
+                croak_memory_wrap();
+            need += (SvCUR(sv) + 1);
+
+            SvGROW(sv, need);
 
             p = SvEND(sv);
             if (esignlen && fill == '0') {
@@ -13100,6 +13117,7 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
                 SvUTF8_on(sv);
             *p = '\0';
             SvCUR_set(sv, p - SvPVX_const(sv));
+        }
 
        if (vectorize) {
            esignlen = 0;