win32: code shrink Unix-style path handling

Replace auto_add_system_drive() with alloc_system_drive() which
leaves space for a possible filename extension.  This makes it
possible to drop alloc_win32_extension() and auto_win32_extension().

Saves 144 bytes.

2 files changed, 16 insertions, 42 deletions

diff --git a/win32/mingw.c b/win32/mingw.c
index 4ffc49e9a..051dc3c0d 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -1496,25 +1496,6 @@ int add_win32_extension(char *p)
         return FALSE;
 }
 
-/* Check if path can be made into an executable by adding a suffix.
- * Return an allocated string containing the path if it can;
- * return NULL if not.
- *
- * If path already has a suffix don't even bother trying.
- */
-char *alloc_win32_extension(const char *p)
-{
-        if (!has_exe_suffix_or_dot(p)) {
-                int len = strlen(p);
-                char *path = strcpy(xmalloc(len+5), p);
-
-                if (add_win32_extension(path))
-                        return path;
-                free(path);
-        }
-        return NULL;
-}
-
 char * FAST_FUNC bs_to_slash(char *str)
 {
         char *p;
@@ -1706,11 +1687,14 @@ const char *need_system_drive(const char *path)
         return NULL;
 }
 
-/* Add a system drive prefix to 'path' if necessary, else return 'path' */
-char *auto_add_system_drive(const char *path)
+/* Allocate a string long enough to allow a system drive prefix and
+ * file extension to be added to path.  Add the prefix if necessary. */
+char *alloc_system_drive(const char *path)
 {
         const char *sd = need_system_drive(path);
-        return sd ? auto_string(concat_path_file(sd, path)) : (char *)path;
+        char *s = xmalloc(strlen(path) + 5 + (sd ? strlen(sd) : 0));
+        sprintf(s, "%s%s", sd ?: "", path);
+        return s;
 }
 
 int chdir_system_drive(void)
@@ -1822,7 +1806,7 @@ void *get_proc_addr(const char *dll, const char *function,
 int unix_path(const char *path)
 {
         int i;
-        char *p = strdup(path);
+        char *p = xstrdup(path);
 
 #define UNIX_PATHS "/bin\0/usr/bin\0/sbin\0/usr/sbin\0"
         i = index_in_strings(UNIX_PATHS, dirname(p));
diff --git a/win32/process.c b/win32/process.c
index a050ec11d..6e758e601 100644
--- a/win32/process.c
+++ b/win32/process.c
@@ -63,7 +63,6 @@ static int
 parse_interpreter(const char *cmd, interp_t *interp)
 {
         char *path, *t;
-        const char *sd;
         int n;
 
         while (TRUE) {
@@ -89,12 +88,6 @@ parse_interpreter(const char *cmd, interp_t *interp)
                 if (*t == '\0')
                         break;
 
-                sd = need_system_drive(path);
-                if (sd && strlen(sd) == 2) {
-                        path -= 2;
-                        memcpy(path, sd, 2);
-                }
-
                 interp->path = path;
                 interp->name = t;
                 interp->opts = strtok(NULL, "\r\n");
@@ -323,9 +316,9 @@ mingw_spawn_interpreter(int mode, const char *prog, char *const *argv,
         new_argv[nopts+1] = (char *)prog; /* pass absolute path */
         memcpy(new_argv+nopts+2, argv+1, sizeof(*argv)*argc);
 
-        if ((fullpath=alloc_win32_extension(interp.path)) != NULL ||
-                        file_is_executable(interp.path)) {
-                new_argv[0] = fullpath ? fullpath : interp.path;
+        fullpath = alloc_system_drive(interp.path);
+        if (add_win32_extension(fullpath) || file_is_executable(fullpath)) {
+                new_argv[0] = fullpath;
                 ret = mingw_spawn_interpreter(mode, new_argv[0], new_argv, envp, level);
         } else
 #if ENABLE_FEATURE_PREFER_APPLETS || ENABLE_FEATURE_SH_STANDALONE
@@ -349,7 +342,6 @@ static intptr_t
 mingw_spawn_1(int mode, const char *cmd, char *const *argv, char *const *envp)
 {
         char *prog;
-        const char *path;
         intptr_t ret;
 
 #if ENABLE_FEATURE_PREFER_APPLETS || ENABLE_FEATURE_SH_STANDALONE
@@ -358,15 +350,13 @@ mingw_spawn_1(int mode, const char *cmd, char *const *argv, char *const *envp)
         else
 #endif
         if (has_path(cmd)) {
+                char *path = alloc_system_drive(cmd);
+                add_win32_extension(path);
+                ret = mingw_spawn_interpreter(mode, path, argv, envp, 0);
+                free(path);
 #if ENABLE_FEATURE_PREFER_APPLETS || ENABLE_FEATURE_SH_STANDALONE
-                const char *oldcmd = cmd;
-#endif
-                cmd = auto_add_system_drive(cmd);
-                path = auto_win32_extension(cmd);
-                ret = mingw_spawn_interpreter(mode, path ? path : cmd, argv, envp, 0);
-#if ENABLE_FEATURE_PREFER_APPLETS || ENABLE_FEATURE_SH_STANDALONE
-                if (ret == -1 && cmd != oldcmd && unix_path(oldcmd) &&
-                                find_applet_by_name(bb_basename(oldcmd))) {
+                if (ret == -1 && unix_path(cmd) &&
+                                find_applet_by_name(bb_basename(cmd)) >= 0) {
                         return mingw_spawn_applet(mode, argv, envp);
                 }
 #endif