browser: provide tab completion also outside of the working directory

Add a global variable, 'present_path', so that 'cwd_tab_completion()'
knows where the user is in the browser, so that it can try completions
against names in that directory instead of always against names in the
current working directory (where nano was invoked).

This fixes https://savannah.gnu.org/bugs/?47234

.
Signed-off-by: Rishabh Dave <rishabhddave@gmail.com>
Signed-off-by: Benno Schulenberg <bensberg@justemail.net>

src/browser.c

@@ -41,8 +41,6 @@ static int longest = 0;
 	/* The number of columns in the longest filename in the list. */
 static size_t selected = 0;
 	/* The currently selected filename in the list; zero-based. */
-static char *path_save = NULL;
-	/* A copy of the current path. */
 
 /* Our main file browser function.  path is the tilde-expanded path we
  * start browsing from. */
@@ -75,7 +73,7 @@ char *do_browser(char *path, DIR *dir)
     path = mallocstrassn(path, get_full_path(path));
 
     /* Save the current path in order to be used later. */
-    path_save = path;
+    present_path = mallocstrcpy(present_path, path);
 
     assert(path != NULL && path[strlen(path) - 1] == '/');
 
@@ -117,7 +115,7 @@ char *do_browser(char *path, DIR *dir)
 #ifndef NANO_TINY
 	if (kbinput == KEY_WINCH) {
 	    /* Rebuild the file list and sort it. */
-	    browser_init(path_save, opendir(path_save));
+	    browser_init(present_path, opendir(present_path));
 	    qsort(filelist, filelist_len, sizeof(char *), diralphasort);
 
 	    /* Make sure the selected file is within range. */
@@ -545,7 +543,7 @@ void browser_refresh(void)
     char *info;
 	/* The additional information that we'll display about a file. */
 
-    titlebar(path_save);
+    titlebar(present_path);
     blank_edit();
 
     wmove(edit, 0, 0);

src/files.c

@@ -1120,6 +1120,8 @@ void do_insertfile(
 		_("File to insert [from %s] ");
 	}
 
+	present_path = mallocstrcpy(present_path, "./");
+
 	i = do_prompt(TRUE,
 #ifndef DISABLE_TABCOMP
 		TRUE,
@@ -2280,6 +2282,8 @@ int do_writeout(bool exiting)
 		  (append == APPEND) ? _("File Name to Append to") :
 		  _("File Name to Write");
 
+	present_path = mallocstrcpy(present_path, "./");
+
 	/* If we're using restricted mode, and the filename isn't blank,
 	 * disable tab completion. */
 	i = do_prompt(!ISSET(RESTRICTED) ||
@@ -2684,10 +2688,16 @@ char **cwd_tab_completion(const char *buf, bool allow_files, size_t
 	/* Cut off the filename part after the slash. */
 	*slash = '\0';
 	dirname = real_dir_from_tilde(dirname);
+	/* A non-absolute path is relative to the current browser directory. */
+	if (dirname[0] != '/') {
+	    dirname = charealloc(dirname, strlen(present_path) +
+						strlen(wasdirname) + 1);
+	    sprintf(dirname, "%s%s", present_path, wasdirname);
+	}
 	free(wasdirname);
     } else {
 	filename = dirname;
-	dirname = mallocstrcpy(NULL, "./");
+	dirname = mallocstrcpy(NULL, present_path);
     }
 
     assert(dirname[strlen(dirname) - 1] == '/');
@@ -2784,7 +2794,7 @@ char *input_tab(char *buf, bool allow_files, size_t *place,
 	beep();
     else {
 	size_t match, common_len = 0;
-	char *mzero;
+	char *mzero, *glued;
 	const char *lastslash = revstrstr(buf, "/", buf + *place);
 	size_t lastslash_len = (lastslash == NULL) ? 0 : lastslash - buf + 1;
 	char *match1 = charalloc(mb_cur_max());
@@ -2820,9 +2830,13 @@ char *input_tab(char *buf, bool allow_files, size_t *place,
 	common_len += lastslash_len;
 	mzero[common_len] = '\0';
 
+	/* Cover also the case of the user specifying a relative path. */
+	glued = charalloc(strlen(present_path) + strlen(mzero) + 1);
+	sprintf(glued, "%s%s", present_path, mzero);
+
 	assert(common_len >= *place);
 
-	if (num_matches == 1 && is_dir(mzero)) {
+	if (num_matches == 1 && (is_dir(mzero) || is_dir(glued))) {
 	    mzero[common_len++] = '/';
 
 	    assert(common_len > *place);
@@ -2892,6 +2906,7 @@ char *input_tab(char *buf, bool allow_files, size_t *place,
 	    *listed = TRUE;
 	}
 
+	free(glued);
 	free(mzero);
     }
 

src/global.c

@@ -57,6 +57,9 @@ ssize_t wrap_at = -CHARS_FROM_EOL;
 char *last_search = NULL;
 	/* The last string we searched for. */
 
+char *present_path = NULL;
+	/* The current browser directory when trying to do tab completion. */
+
 unsigned flags[4] = {0, 0, 0, 0};
 	/* Our flag containing the states of all global options. */
 WINDOW *topwin;
@@ -1647,6 +1650,7 @@ void thanks_for_all_the_fish(void)
 #endif
     free(answer);
     free(last_search);
+    free(present_path);
 #ifndef DISABLE_SPELLER
     free(alt_speller);
 #endif

src/proto.h

@@ -46,6 +46,8 @@ extern ssize_t wrap_at;
 
 extern char *last_search;
 
+extern char *present_path;
+
 extern unsigned flags[4];
 extern WINDOW *topwin;
 extern WINDOW *edit;