2 files changed, 34 insertions, 22 deletions

diff --git a/win32/mingw.c b/win32/mingw.c
index 707e6a3d2..08d955527 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -1160,7 +1160,7 @@ int mingw_rmdir(const char *path)
         return rmdir(path);
 }
 
-const char win_suffix[4][4] = { "com", "exe", "bat", "cmd" };
+static const char win_suffix[4][4] = { "com", "exe", "bat", "cmd" };
 
 static int has_win_suffix(const char *name, int start)
 {
@@ -1191,33 +1191,45 @@ int has_exe_suffix_or_dot(const char *name)
         return last_char_is(name, '.') || has_win_suffix(name, 0);
 }
 
-/* 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.
+/* Check if path can be made into an executable by adding a suffix.
+ * The suffix is added to the end of the argument which must be
+ * long enough to allow this.
  *
- * if path already has a suffix don't even bother trying
+ * If the return value is TRUE the argument contains the new path,
+ * if FALSE the argument is unchanged.
  */
-char *add_win32_extension(const char *p)
+int add_win32_extension(char *p)
 {
-        char *path;
-        int i, len;
-
-        if (has_exe_suffix_or_dot(p)) {
-                return NULL;
+        if (!has_exe_suffix_or_dot(p)) {
+                int i, len = strlen(p);
+
+                p[len] = '.';
+                for (i=0; i<4; ++i) {
+                        memcpy(p+len+1, win_suffix[i], 4);
+                        if (file_is_executable(p))
+                                return TRUE;
+                }
+                p[len] = '\0';
         }
+        return FALSE;
+}
 
-        len = strlen(p);
-        path = xasprintf("%s.com", p);
+/* 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);
 
-        for (i=0; i<4; ++i) {
-                memcpy(path+len+1, win_suffix[i], 4);
-                if (file_is_executable(path)) {
+                if (add_win32_extension(path))
                         return path;
-                }
+                free(path);
         }
-
-        free(path);
-
         return NULL;
 }
 
diff --git a/win32/process.c b/win32/process.c
index e9b34b56d..b7f02e431 100644
--- a/win32/process.c
+++ b/win32/process.c
@@ -240,7 +240,7 @@ spawnveq(int mode, const char *path, char *const *argv, char *const *env)
                         p = strdup(new_argv[0]);
                 }
                 else {
-                        p = add_win32_extension(new_argv[0]);
+                        p = alloc_win32_extension(new_argv[0]);
                 }
 
                 if (p != NULL && has_bat_suffix(p)) {
@@ -307,7 +307,7 @@ mingw_spawn_interpreter(int mode, const char *prog, char *const *argv, char *con
         new_argv[nopts+1] = (char *)prog; /* pass absolute path */
         memcpy(new_argv+nopts+2, argv+1, sizeof(*argv)*argc);
 
-        if ((fullpath=add_win32_extension(interp.path)) != NULL ||
+        if ((fullpath=alloc_win32_extension(interp.path)) != NULL ||
                         file_is_executable(interp.path)) {
                 new_argv[0] = fullpath ? fullpath : interp.path;
                 ret = spawnveq(mode, new_argv[0], new_argv, envp);