win32: improve handling of 'c:file' paths for executables

bb_basename() didn't properly handle paths of the form 'c:file'.
Attempting to run 'c:busybox' resulted in 'c:busybox: applet not found'.

The shell had a similar problem: trying to run 'c:busybox' reported
'sh: c:busybox: not found'.

2 files changed, 11 insertions, 3 deletions

diff --git a/libbb/get_last_path_component.c b/libbb/get_last_path_component.c
index 3a9b9237e..00649620d 100644
--- a/libbb/get_last_path_component.c
+++ b/libbb/get_last_path_component.c
@@ -13,7 +13,7 @@ const char* FAST_FUNC bb_basename(const char *name)
 #if ENABLE_PLATFORM_MINGW32
         const char *cp;
         for (cp = name; *cp; cp++)
-                if (*cp == '/' || *cp == '\\')
+                if (*cp == '/' || *cp == '\\' || *cp == ':')
                         name = cp + 1;
 #else
         const char *cp = strrchr(name, '/');
diff --git a/shell/ash.c b/shell/ash.c
index 47ad85440..6a03ef6b4 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -8729,7 +8729,11 @@ static void shellexec(char *prog, char **argv, const char *path, int idx)
         int applet_no = -1; /* used only by FEATURE_SH_STANDALONE */
 
         envp = listvars(VEXPORT, VUNSET, /*strlist:*/ NULL, /*end:*/ NULL);
-        if ((strchr(prog, '/') || (ENABLE_PLATFORM_MINGW32 && strchr(prog, '\\')))
+#if ENABLE_PLATFORM_MINGW32
+        if ((strchr(prog, '/') || strchr(prog, '\\') || has_dos_drive_prefix(prog))
+#else
+        if (strchr(prog, '/') != NULL
+#endif
 #if ENABLE_FEATURE_SH_STANDALONE
          || (applet_no = find_applet_by_name(prog)) >= 0
 #endif
@@ -14235,7 +14239,11 @@ find_command(char *name, struct cmdentry *entry, int act, const char *path)
         int len;
 
         /* If name contains a slash, don't use PATH or hash table */
-        if (strchr(name, '/') || (ENABLE_PLATFORM_MINGW32 && strchr(name, '\\'))) {
+#if ENABLE_PLATFORM_MINGW32
+        if (strchr(name, '/') || strchr(name, '\\') || has_dos_drive_prefix(name)) {
+#else
+        if (strchr(name, '/' != NULL) {
+#endif
                 entry->u.index = -1;
                 if (act & DO_ABS) {
 #if ENABLE_PLATFORM_MINGW32