[SV 63552] Change directories before constructing include paths

* src/makeint.h (reset_makeflags): New function to handle changing
MAKEFLAGS from within makefiles.  Remove decode_env_switches().
* src/variable.c (set_special_var): Call reset_makeflags() instead
of various internal methods.
* src/main.c (decode_env_switches): Only internal now so make static.
(decode_switches): Don't invoke construct_include_path() yet.
(reset_makeflags): Decode env switches and construct include paths.
(main): Construct include paths after we process -C options.
* tests/scripts/options/dash-C: Rewrite to use new test constructs.
Add a test using both -C and -I together.
Add a test for multiple -C options.

1 files changed, 4 insertions, 6 deletions

diff --git a/src/variable.c b/src/variable.c
index d8bf4288..1b1cb743 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -1217,18 +1217,16 @@ target_environment (struct file *file, int recursive)
 static struct variable *
 set_special_var (struct variable *var, enum variable_origin origin)
 {
-  if (streq (var->name, RECIPEPREFIX_NAME))
+  if (streq (var->name, MAKEFLAGS_NAME))
+    reset_makeflags (origin);
+
+  else if (streq (var->name, RECIPEPREFIX_NAME))
     {
       /* The user is resetting the command introduction prefix.  This has to
          happen immediately, so that subsequent rules are interpreted
          properly.  */
       cmd_prefix = var->value[0]=='\0' ? RECIPEPREFIX_DEFAULT : var->value[0];
     }
-  else if (streq (var->name, MAKEFLAGS_NAME))
-    {
-      decode_env_switches (STRING_SIZE_TUPLE(MAKEFLAGS_NAME), origin);
-      define_makeflags (rebuilding_makefiles);
-    }
 
   return var;
 }