Reset preview window flags that are not style-related

Fix #2203

4 files changed, 41 insertions, 14 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 97d877d7..8aae9e54 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,12 @@
 CHANGELOG
 =========
 
+0.23.1
+------
+- Reset `hidden` flag and scroll offset of `--preview-window` if another
+  `--preview-window` is found. We should only keep style-related flags across
+  multiple `--preview-window` options.
+
 0.23.0
 ------
 - Support preview scroll offset relative to window height
diff --git a/man/man1/fzf.1 b/man/man1/fzf.1
index cfa4adb6..22171be3 100644
--- a/man/man1/fzf.1
+++ b/man/man1/fzf.1
@@ -381,11 +381,21 @@ Preview window will be updated even when there is no match for the current
 query if any of the placeholder expressions evaluates to a non-empty string.
 .RE
 .TP
-.BI "--preview-window=" "[POSITION][:SIZE[%]][:rounded|sharp|noborder][:wrap][:hidden][:+SCROLL[-OFFSET]]"
-Determines the layout of the preview window. If the argument contains
+.BI "--preview-window=" "[POSITION][:SIZE[%]][:rounded|sharp|noborder][:wrap][:cycle][:hidden][:+SCROLL[-OFFSET]]"
+
+.RS
+.B POSITION: (default: right)
+    \fBup
+    \fBdown
+    \fBleft
+    \fBright
+.RE
+
+\fRDetermines the layout of the preview window. If the argument contains
 \fB:hidden\fR, the preview window will be hidden by default until
 \fBtoggle-preview\fR action is triggered. Long lines are truncated by default.
-Line wrap can be enabled with \fB:wrap\fR flag.
+Line wrap can be enabled with \fB:wrap\fR flag. Cyclic scrolling is enabled
+with \fB:cycle\fR flag.
 
 If size is given as 0, preview window will not be visible, but fzf will still
 execute the command in the background.
@@ -402,14 +412,6 @@ be given as a numeric integer (\fB-INTEGER\fR), or as a denominator form
 (\fB-/INTEGER\fR) for specifying a fraction of the preview window height.
 
 .RS
-.B POSITION: (default: right)
-    \fBup
-    \fBdown
-    \fBleft
-    \fBright
-.RE
-
-.RS
 e.g.
      \fB# Non-default scroll window positions and sizes
      fzf --preview="head {}" --preview-window=up:30%
@@ -427,6 +429,19 @@ e.g.
            --preview-window +{2}-/2\fR
 
 .RE
+
+You can write style-related flags across multiple \fB--preview-window\fR
+options. But flags that are not style-related such as \fBhidden\fR and scroll
+offset are only allowed in the last \fB--preview-window\fR.
+
+.RS
+e.g.
+    export FZF_DEFAULT_OPTS='--preview-window sharp:cycle'
+
+    # sharp + cycle + up + 50%
+    fzf --preview-window 'up' --preview-window '50%' --preview 'bat {}'
+.RE
+
 .SS Scripting
 .TP
 .BI "-q, --query=" "STR"
diff --git a/src/options.go b/src/options.go
index 35220bae..c7354b35 100644
--- a/src/options.go
+++ b/src/options.go
@@ -994,6 +994,10 @@ func parseInfoStyle(str string) infoStyle {
 }
 
 func parsePreviewWindow(opts *previewOpts, input string) {
+	// We should reset flags that are not style-related.
+	opts.hidden = false
+	opts.scroll = ""
+
 	tokens := strings.Split(input, ":")
 	sizeRegex := regexp.MustCompile("^[0-9]+%?$")
 	offsetRegex := regexp.MustCompile("^\\+([0-9]+|{-?[0-9]+})(-[0-9]+|-/[1-9][0-9]*)?$")
diff --git a/src/options_test.go b/src/options_test.go
index 457c6c15..38873738 100644
--- a/src/options_test.go
+++ b/src/options_test.go
@@ -387,21 +387,23 @@ func TestPreviewOpts(t *testing.T) {
 		opts.Preview.size.size == 50) {
 		t.Error()
 	}
-	opts = optsFor("--preview", "cat {}", "--preview-window=left:15:hidden:wrap")
+	opts = optsFor("--preview", "cat {}", "--preview-window=left:15:hidden:wrap:+{1}-/2")
 	if !(opts.Preview.command == "cat {}" &&
 		opts.Preview.hidden == true &&
 		opts.Preview.wrap == true &&
 		opts.Preview.position == posLeft &&
+		opts.Preview.scroll == "{1}-/2" &&
 		opts.Preview.size.percent == false &&
 		opts.Preview.size.size == 15) {
 		t.Error(opts.Preview)
 	}
-	opts = optsFor("--preview-window=up:15:wrap:hidden", "--preview-window=down", "--preview-window=cycle")
+	opts = optsFor("--preview-window=up:15:wrap:hidden:+{1}-/2", "--preview-window=down", "--preview-window=cycle")
 	if !(opts.Preview.command == "" &&
-		opts.Preview.hidden == true &&
+		opts.Preview.hidden == false &&
 		opts.Preview.wrap == true &&
 		opts.Preview.cycle == true &&
 		opts.Preview.position == posDown &&
+		opts.Preview.scroll == "" &&
 		opts.Preview.size.percent == false &&
 		opts.Preview.size.size == 15) {
 		t.Error(opts.Preview.size.size)