win32: shrink code to detect .exe files

Add a function (has_exe_suffix) to replace explicit code to check
if a filename ends with '.exe. or '.com'.

Also shrink code that checks for '.exe' or '.com' on PATH in shell's
find_command function.

4 files changed, 26 insertions, 31 deletions

diff --git a/include/mingw.h b/include/mingw.h
index d7dabacaf..dd676bf2c 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -471,6 +471,7 @@ char **env_setenv(char **env, const char *name);
 const char *get_busybox_exec_path(void);
 void init_winsock(void);
 
+int has_exe_suffix(const char *p);
 char *file_is_win32_executable(const char *p);
 
 int err_win_to_posix(DWORD winerr);
diff --git a/shell/ash.c b/shell/ash.c
index af0c68dcf..e47836d70 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -13564,10 +13564,7 @@ find_command(char *name, struct cmdentry *entry, int act, const char *path)
                         goto success;
                 }
 #if ENABLE_PLATFORM_MINGW32
-                len = strlen(fullname);
-                if (len > 4 &&
-                    (!strcasecmp(fullname+len-4, ".exe") ||
-                     !strcasecmp(fullname+len-4, ".com"))) {
+                if (has_exe_suffix(fullname)) {
                         if (stat(fullname, &statb) < 0) {
                                 if (errno != ENOENT && errno != ENOTDIR)
                                         e = errno;
@@ -13576,14 +13573,12 @@ find_command(char *name, struct cmdentry *entry, int act, const char *path)
                 }
                 else {
                         /* path_advance() has reserved space for .exe */
-                        memcpy(fullname+len, ".exe", 5);
+                        len = strlen(fullname);
+                        strcat(fullname, ".exe");
                         if (stat(fullname, &statb) < 0) {
-                                if (errno != ENOENT && errno != ENOTDIR)
-                                        e = errno;
                                 memcpy(fullname+len, ".com", 5);
                                 if (stat(fullname, &statb) < 0) {
-                                        if (errno != ENOENT && errno != ENOTDIR)
-                                                e = errno;
+                                        /* check for script */
                                         fullname[len] = '\0';
                                         if (stat(fullname, &statb) < 0) {
                                                 if (errno != ENOENT && errno != ENOTDIR)
diff --git a/win32/mingw.c b/win32/mingw.c
index 1170cd9d5..7f37eadda 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -240,15 +240,12 @@ static int do_lstat(int follow, const char *file_name, struct mingw_stat *buf)
         mode_t usermode;
 
         if (!(err = get_file_attr(file_name, &fdata))) {
-                int len = strlen(file_name);
-
                 buf->st_ino = 0;
                 buf->st_uid = DEFAULT_UID;
                 buf->st_gid = DEFAULT_GID;
                 buf->st_nlink = 1;
                 buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes);
-                if (len > 4 && (!strcasecmp(file_name+len-4, ".exe") ||
-                                                !strcasecmp(file_name+len-4, ".com")))
+                if (has_exe_suffix(file_name))
                         buf->st_mode |= S_IEXEC;
                 buf->st_size = fdata.nFileSizeLow |
                         (((off64_t)fdata.nFileSizeHigh)<<32);
@@ -1002,6 +999,14 @@ int mingw_rmdir(const char *path)
         return rmdir(path);
 }
 
+int has_exe_suffix(const char *name)
+{
+        int len = strlen(name);
+
+        return len > 4 && (!strcasecmp(name+len-4, ".exe") ||
+                                !strcasecmp(name+len-4, ".com"));
+}
+
 /* 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.
@@ -1011,26 +1016,23 @@ int mingw_rmdir(const char *path)
 char *file_is_win32_executable(const char *p)
 {
         char *path;
-        int len = strlen(p);
 
-        if (len > 4 && (!strcasecmp(p+len-4, ".exe") ||
-                                        !strcasecmp(p+len-4, ".com"))) {
+        if (has_exe_suffix(p)) {
                 return NULL;
         }
 
-        if ( (path=malloc(len+5)) != NULL ) {
-                memcpy(path, p, len);
-                memcpy(path+len, ".exe", 5);
-                if (file_is_executable(path)) {
-                        return path;
-                }
-                memcpy(path+len, ".com", 5);
-                if (file_is_executable(path)) {
-                        return path;
-                }
-                free(path);
+        path = xasprintf("%s.exe", p);
+        if (file_is_executable(path)) {
+                return path;
         }
 
+        memcpy(path+strlen(p), ".com", 5);
+        if (file_is_executable(path)) {
+                return path;
+        }
+
+        free(path);
+
         return NULL;
 }
 
diff --git a/win32/process.c b/win32/process.c
index 5eb52828b..919d46043 100644
--- a/win32/process.c
+++ b/win32/process.c
@@ -52,10 +52,7 @@ parse_interpreter(const char *cmd, char ***opts, int *nopts)
         *opts = opt;
 
         /* don't even try a .exe */
-        n = strlen(cmd);
-        if (n >= 4 &&
-            (!strcasecmp(cmd+n-4, ".exe") ||
-             !strcasecmp(cmd+n-4, ".com")))
+        if (has_exe_suffix(cmd))
                 return NULL;
 
         fd = open(cmd, O_RDONLY);