* fix for SIGSEGV in Exec without command line parameters revealed in discussion for #26160

git-svn-id: trunk@27804 -

rtl/go32v2/dos.pp

@@ -436,8 +436,7 @@ begin
   seg_move (get_ds, PtrInt (ExecBufPtr), DosMemSelector, TB, Pred (Current_Dos_Buffer_Pos));
 { allocate FCB see dosexec code }
   arg_ofs:=1;
-  while (c[arg_ofs] in [' ',#9]) and
-   (arg_ofs<length(c)) do
+  while (arg_ofs<length(c)) and (c[arg_ofs] in [' ',#9]) do
     inc(arg_ofs);
   dosregs.ax:=$2901;
   dosregs.ds:=(la_c+arg_ofs) shr 4;

rtl/msdos/dos.pp

@@ -237,8 +237,7 @@ begin
     GetShortName(p);
   { allocate FCB see dosexec code }
   arg_ofs:=1;
-  while (c[arg_ofs] in [' ',#9]) and
-   (arg_ofs<length(c)) do
+  while (arg_ofs<length(c)) and (c[arg_ofs] in [' ',#9]) do
     inc(arg_ofs);
   dosregs.ax:=$2901;
   dosregs.ds:=Seg(c[arg_ofs]);

rtl/watcom/dos.pp

@@ -228,7 +228,7 @@ begin
   la_e:=la_e+16;
 { allocate FCB see dosexec code }
   arg_ofs:=1;
-  while (c[arg_ofs] in [' ',#9]) do
+  while (arg_ofs < Length (C)) and (c[arg_ofs] in [' ',#9]) do
    inc(arg_ofs);
   dosregs.ax:=$2901;
   dosregs.ds:=(la_c+arg_ofs) shr 4;
@@ -239,12 +239,12 @@ begin
 { allocate second FCB see dosexec code }
   repeat
     inc(arg_ofs);
-  until (c[arg_ofs] in [' ',#9,#13]);
-  if c[arg_ofs]<>#13 then
+  until (Arg_Ofs >= Length (C)) or (c[arg_ofs] in [' ',#9,#13]);
+  if (c[arg_ofs]<>#13) and (Arg_Ofs < Length (C)) then
    begin
      repeat
        inc(arg_ofs);
-     until not (c[arg_ofs] in [' ',#9]);
+     until (Arg_Ofs > Length (C)) or not (c[arg_ofs] in [' ',#9]);
    end;
   dosregs.ax:=$2901;
   dosregs.ds:=(la_c+arg_ofs) shr 4;