It was impossible to enter a file:// URL because it got interpreted
as a 'f' command without any warning about invalid argument. The same
thing happened with relative addresses beginning with 'b' or 'f'.
---
 src/gmnlm.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/gmnlm.c b/src/gmnlm.c
index 9e7b527..8b1dfb4 100644
--- a/src/gmnlm.c
+++ b/src/gmnlm.c
@@ -569,8 +569,10 @@ do_prompts(const char *prompt, struct browser *browser)
 		result = PROMPT_QUIT;
 		goto exit;
 	case 'b':
-		if (in[1]) {
+		if (in[1] && isdigit(in[1])) {
 			historyhops =(int)strtol(in+1, &endptr, 10);
+		} else if (in[1]) {
+			break;
 		}
 		while (historyhops > 0) {
 			if (browser->history->prev) {
@@ -582,8 +584,10 @@ do_prompts(const char *prompt, struct browser *browser)
 		result = PROMPT_ANSWERED;
 		goto exit;
 	case 'f':
-		if (in[1]) {
+		if (in[1] && isdigit(in[1])) {
 			historyhops =(int)strtol(in+1, &endptr, 10);
+		} else if (in[1]) {
+			break;
 		}
 		while (historyhops > 0) {
 			if (browser->history->next) {
-- 
2.36.1