userdiff: add built-in pattern for CSS

CSS is widely used, motivating it being included as a built-in pattern.

It must be noted that the word_regex for CSS (i.e. the regex defining
what is a word in the language) does not consider '.' and '#' characters
(in CSS selectors) to be part of the word. This behavior is documented
by the test t/t4018/css-rule.
The logic behind this behavior is the following: identifiers in CSS
selectors are identifiers in a HTML/XML document. Therefore, the '.'/'#'
character are not part of the identifier, but an indicator of the nature
of the identifier in HTML/XML (class or id). Diffing ".class1" and
".class2" must show that the class name is changed, but we still are
selecting a class.

Logic behind the "pattern" regex is:
    1. reject lines ending with a colon/semicolon (properties)
    2. if a line begins with a name in column 1, pick the whole line

Credits to Johannes Sixt (j6t@kdbg.org) for the pattern regex and most
of the tests.

Signed-off-by: William Duclot <william.duclot@ensimag.grenoble-inp.fr>
Signed-off-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

13 files changed, 76 insertions, 0 deletions

diff --git a/t/t4018-diff-funcname.sh b/t/t4018-diff-funcname.sh
index 67373dc..1795ffc 100755
--- a/t/t4018-diff-funcname.sh
+++ b/t/t4018-diff-funcname.sh
@@ -30,6 +30,7 @@ diffpatterns="
 	bibtex
 	cpp
 	csharp
+	css
 	fortran
 	fountain
 	html
diff --git a/t/t4018/css-brace-in-col-1 b/t/t4018/css-brace-in-col-1
new file mode 100644
index 0000000..7831577
--- /dev/null
+++ b/t/t4018/css-brace-in-col-1
@@ -0,0 +1,5 @@
+RIGHT label.control-label
+{
+    margin-top: 10px!important;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-colon-eol b/t/t4018/css-colon-eol
new file mode 100644
index 0000000..5a30553
--- /dev/null
+++ b/t/t4018/css-colon-eol
@@ -0,0 +1,4 @@
+RIGHT h1 {
+color:
+ChangeMe;
+}
diff --git a/t/t4018/css-colon-selector b/t/t4018/css-colon-selector
new file mode 100644
index 0000000..c6d71fb
--- /dev/null
+++ b/t/t4018/css-colon-selector
@@ -0,0 +1,5 @@
+RIGHT a:hover {
+    margin-top:
+    10px!important;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-common b/t/t4018/css-common
new file mode 100644
index 0000000..84ed754
--- /dev/null
+++ b/t/t4018/css-common
@@ -0,0 +1,4 @@
+RIGHT label.control-label {
+    margin-top: 10px!important;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-long-selector-list b/t/t4018/css-long-selector-list
new file mode 100644
index 0000000..7ccd25d
--- /dev/null
+++ b/t/t4018/css-long-selector-list
@@ -0,0 +1,6 @@
+p.header,
+label.control-label,
+div ul#RIGHT {
+    margin-top: 10px!important;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-prop-sans-indent b/t/t4018/css-prop-sans-indent
new file mode 100644
index 0000000..a9e3c86
--- /dev/null
+++ b/t/t4018/css-prop-sans-indent
@@ -0,0 +1,5 @@
+RIGHT, label.control-label {
+margin-top: 10px!important;
+padding: 0;
+border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-short-selector-list b/t/t4018/css-short-selector-list
new file mode 100644
index 0000000..6a0bdee
--- /dev/null
+++ b/t/t4018/css-short-selector-list
@@ -0,0 +1,4 @@
+label.control, div ul#RIGHT {
+    margin-top: 10px!important;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-trailing-space b/t/t4018/css-trailing-space
new file mode 100644
index 0000000..32b5606
--- /dev/null
+++ b/t/t4018/css-trailing-space
@@ -0,0 +1,5 @@
+RIGHT label.control-label {
+    margin:10px;   
+    padding:10px;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4034-diff-words.sh b/t/t4034-diff-words.sh
index f2f55fc..912df91 100755
--- a/t/t4034-diff-words.sh
+++ b/t/t4034-diff-words.sh
@@ -302,6 +302,7 @@ test_language_driver ada
 test_language_driver bibtex
 test_language_driver cpp
 test_language_driver csharp
+test_language_driver css
 test_language_driver fortran
 test_language_driver html
 test_language_driver java
diff --git a/t/t4034/css/expect b/t/t4034/css/expect
new file mode 100644
index 0000000..ed10393
--- /dev/null
+++ b/t/t4034/css/expect
@@ -0,0 +1,16 @@
+<BOLD>diff --git a/pre b/post<RESET>
+<BOLD>index b8ae0bb..fe500b7 100644<RESET>
+<BOLD>--- a/pre<RESET>
+<BOLD>+++ b/post<RESET>
+<CYAN>@@ -1,10 +1,10 @@<RESET>
+.<RED>class-form<RESET><GREEN>other-form<RESET> label.control-label {
+    margin-top: <RED>10<RESET><GREEN>15<RESET>px!important;
+    border : 10px <RED>dashed<RESET><GREEN>dotted<RESET> #C6C6C6;
+}<RESET>
+<RED>#CCCCCC<RESET><GREEN>#CCCCCB<RESET>
+10em<RESET>
+<RED>padding-bottom<RESET><GREEN>margin-left<RESET>
+150<RED>px<RESET><GREEN>em<RESET>
+10px
+<RED>!important<RESET>
+<RED>div<RESET><GREEN>li<RESET>.class#id
diff --git a/t/t4034/css/post b/t/t4034/css/post
new file mode 100644
index 0000000..fe500b7
--- /dev/null
+++ b/t/t4034/css/post
@@ -0,0 +1,10 @@
+.other-form label.control-label {
+    margin-top: 15px!important;
+    border : 10px dotted #C6C6C6;
+}
+#CCCCCB
+10em
+margin-left
+150em
+10px
+li.class#id
diff --git a/t/t4034/css/pre b/t/t4034/css/pre
new file mode 100644
index 0000000..b8ae0bb
--- /dev/null
+++ b/t/t4034/css/pre
@@ -0,0 +1,10 @@
+.class-form label.control-label {
+    margin-top: 10px!important;
+    border : 10px dashed #C6C6C6;
+}
+#CCCCCC
+10em
+padding-bottom
+150px
+10px!important
+div.class#id