new feature: a bindable function that starts always a backward search

doc/nano.texi

@@ -1087,8 +1087,11 @@ Inserts a file into the current buffer (at the current cursor position),
 or into a new buffer when option @code{multibuffer} is set.
 
 @item whereis
-Searches for text in the current buffer --- or for filenames matching
+Starts a forward search for text in the current buffer --- or for filenames
-a string in the current list in the file browser
+matching a string in the current list in the file browser.
+
+@item wherewas
+Starts a backward search for text in the current buffer.
 
 @item searchagain
 Repeats the last search command without prompting.

doc/nanorc.5

@@ -443,8 +443,11 @@ Inserts a file into the current buffer (at the current cursor position),
 or into a new buffer when option \fBmultibuffer\fR is set.
 .TP
 .B whereis
-Searches for text in the current buffer -- or for filenames matching
+Starts a forward search for text in the current buffer -- or for filenames
-a string in the current list in the file browser.
+matching a string in the current list in the file browser.
+.TP
+.B wherewas
+Starts a backward search for text in the current buffer.
 .TP
 .B searchagain
 Repeats the last search command without prompting.

src/global.c

@@ -534,6 +534,8 @@ void shortcut_init(void)
 	N_("Insert another file into the current one");
     const char *nano_whereis_msg =
 	N_("Search for a string or a regular expression");
+    const char *nano_wherewas_msg =
+	N_("Search backward for a string or expression");
 #ifdef ENABLE_BROWSER
     const char *nano_browser_whereis_msg = N_("Search for a string");
     const char *nano_browser_refresh_msg = N_("Refresh the file list");
@@ -974,6 +976,9 @@ void shortcut_init(void)
 	N_("Comment Lines"), IFSCHELP(nano_comment_msg), BLANKAFTER, NOVIEW);
 #endif
 #ifndef NANO_TINY
+    add_to_funcs(do_search_backward, MMAIN,
+	N_("Where Was"), IFSCHELP(N_(nano_wherewas_msg)), BLANKAFTER, VIEW);
+
     add_to_funcs(do_savefile, MMAIN,
 	N_("Save"), IFSCHELP(nano_savefile_msg), BLANKAFTER, NOVIEW);
 #endif
@@ -1462,7 +1467,9 @@ sc *strtosc(const char *input)
     else if (!strcasecmp(input, "insert"))
 	s->scfunc = do_insertfile_void;
     else if (!strcasecmp(input, "whereis"))
-	s->scfunc = do_search;
+	s->scfunc = do_search_forward;
+    else if (!strcasecmp(input, "wherewas"))
+	s->scfunc = do_search_backward;
     else if (!strcasecmp(input, "searchagain") ||
 	     !strcasecmp(input, "research"))  /* Deprecated.  Remove in 2018. */
 	s->scfunc = do_research;

src/proto.h

@@ -502,6 +502,8 @@ void search_replace_abort(void);
 int findnextstr(const char *needle, bool whole_word_only, bool have_region,
 	size_t *match_len, bool skipone, const filestruct *begin, size_t begin_x);
 void do_search(void);
+void do_search_forward(void);
+void do_search_backward(void);
 #ifndef NANO_TINY
 void do_findprevious(void);
 void do_findnext(void);

src/search.c

@@ -374,6 +374,20 @@ void do_search(void)
 	go_looking();
 }
 
+/* Search forward for a string. */
+void do_search_forward(void)
+{
+    UNSET(BACKWARDS_SEARCH);
+    do_search();
+}
+
+/* Search backwards for a string. */
+void do_search_backward(void)
+{
+    SET(BACKWARDS_SEARCH);
+    do_search();
+}
+
 #ifndef NANO_TINY
 /* Search in the backward direction for the next occurrence. */
 void do_findprevious(void)