This change fixes the history pruning treatment of a slash

character in the history followed by the name of the history
command.

The purpose of pruning is to avoid recursion in the history
rewind, so history lines with a history command in them are
pruned away in the search.

With the history command named as "-", previously a history
line like:

        find / --option

would have been pruned (too aggressively). The change trims
whitespace after first considering the case of whitespace
separating a slash and the name of the history command.

A few basic unit tests for the history command are also added
with this commit.

Makefile

@@ -82,11 +82,14 @@ version.h: Makefile .git/index
 	@echo "CC $@"
 	$(CC) $(_CPPFLAGS) $(_CFLAGS) -o $@ $<
 
-check: trip
+check: trip testhist
 
 trip: rc tripping
 	./rc -p <"$(srcdir)/trip.rc"
 
+testhist:
+	cd "$(srcdir)/test-history" && make
+
 acutest.h:; wget --compression=gzip https://raw.githubusercontent.com/mity/acutest/master/include/acutest.h
 
 test-bestline.o: test-bestline.c edit-bestline.c acutest.h

history.c

@@ -248,6 +248,8 @@ again:	s = last;
 	for (t = s; *t != '\0'; ++t)
 		if (*t == me) {
 			char *u = t - 1;
+			if (u < s || *u == '/')
+				goto again;
 			while (u >= s && (*u == ' ' || *u == '\t'))
 				--u;
 			if (u < s)
@@ -256,7 +258,6 @@ again:	s = last;
 			case '`': case '@':
 			case '(': case ')':
 			case '{': case '|':
-			case '/':
 				goto again;
 			default:
 				break;

test-history/Makefile

@@ -0,0 +1,40 @@
+all: -p --p \
+	ignore_me.test \
+	match_me_no_syntax.test \
+	match_me_slash_whitespace.test \
+	delete_char.test \
+	delete_char_stepwise.test \
+	insert_char.test \
+	insert_char_skip_tabs.test \
+	replace_space.test \
+	append_char.test \
+	truncate_and_append.test \
+	skip_match.test
+
+ignore_me.test: force
+	@cp $(@:.test=) $@
+	history=$@ ./-p | cmp -n `sed 1q $@ | wc -c` - $@
+	@rm $@
+
+match_me_no_syntax.test \
+match_me_slash_whitespace.test: force
+	@cp $(@:.test=) $@
+	history=$@ ./-p > $(@:.test=.out) && sed -n 2p $@ | cmp - $(@:.test=.out)
+	@rm $@ $(@:.test=.out)
+
+delete_char.test \
+delete_char_stepwise.test \
+insert_char.test \
+insert_char_skip_tabs.test \
+replace_space.test \
+append_char.test \
+truncate_and_append.test \
+skip_match.test: force
+	@cp $(@:.test=) $@
+	sed -n -e /EOF/q -e 1d -e p $@ | history=$@ ./--p >$(@:.test=.out) 2>/dev/null && sed 1q $@ | cmp - $(@:.test=.out)
+	@rm $@ $(@:.test=.out)
+
+-p --p:
+	ln -s ../history $@
+
+force:

test-history/append_char

@@ -0,0 +1,5 @@
+append the second the
+  + the
+
+EOF
+append the second

test-history/delete_char

@@ -0,0 +1,5 @@
+delete the second the
+	   ####
+
+EOF
+delete the the second the

test-history/delete_char_stepwise

@@ -0,0 +1,8 @@
+delete the second the
+	   #
+	   #
+	   #
+	   #
+
+EOF
+delete the the second the

test-history/ignore_me

@@ -0,0 +1,57 @@
+the cases below should all be ignored
+-
+--
+-p
+--p
+./-
+./--
+./-p
+./--p
+  -
+  --
+  -p
+  --p
+	./-
+	./--
+	./-p
+	./--p
+{-}
+{--}
+{-p}
+{--p}
+{ -}
+{ --}
+{ -p}
+{ --p}
+(-)
+(--)
+(-p)
+(--p)
+( -)
+( --)
+( -p)
+( --p)
+()-
+()--
+()-p
+()--p
+@-
+@--
+@-p
+@--p
+@ -
+@ --
+@ -p
+@ --p
+|-
+|--
+|-p
+|--p
+`-
+`--
+`-p
+`--p
+` -
+` --
+` -p
+` --p

test-history/insert_char

@@ -0,0 +1,5 @@
+insert the first the
+       ^the 
+
+EOF
+insert first the

test-history/insert_char_skip_tabs

@@ -0,0 +1,5 @@
+insert after a combination of spaces and tabs near the last position
+                  	 	       	      ^near the last 
+
+EOF
+insert after a combination of spaces and tabs position

test-history/match_me_no_syntax

@@ -0,0 +1,2 @@
+this should match
+echo -- -n

test-history/match_me_slash_whitespace

@@ -0,0 +1,2 @@
+this should match
+find / -- -ls

test-history/replace_space

@@ -0,0 +1,5 @@
+replace     spaces
+        %%% 
+
+EOF
+replace the spaces

test-history/skip_match

@@ -0,0 +1,9 @@
+append the second the
+-
+-
+  + the
+
+EOF
+append the second
+skip this line
+skip this line, too

test-history/truncate_and_append

@@ -0,0 +1,5 @@
+truncate and append
+        $ and append
+
+EOF
+truncate this old stuff