Merge branch 'js/configurable-tab'

* js/configurable-tab:
  Make the tab width used for whitespace checks configurable
  apply --whitespace=fix: fix tab-in-indent

Documentation/config.txt

@@ -522,6 +522,9 @@ core.whitespace::
   part of the line terminator, i.e. with it, `trailing-space`
   does not trigger if the character before such a carriage-return
   is not a whitespace (not enabled by default).
+* `tabwidth=<n>` tells how many character positions a tab occupies; this
+  is relevant for `indent-with-non-tab` and when git fixes `tab-in-indent`
+  errors. The default tab width is 8. Allowed values are 1 to 63.
 
 core.fsyncobjectfiles::
 	This boolean will enable 'fsync()' when writing object files.

Documentation/gitattributes.txt

@@ -723,6 +723,8 @@ control per path.
 Set::
 
 	Notice all types of potential whitespace errors known to git.
+	The tab width is taken from the value of the `core.whitespace`
+	configuration variable.
 
 Unset::
 
@@ -730,13 +732,13 @@ Unset::
 
 Unspecified::
 
-	Use the value of `core.whitespace` configuration variable to
+	Use the value of the `core.whitespace` configuration variable to
 	decide what to notice as error.
 
 String::
 
 	Specify a comma separate list of common whitespace problems to
-	notice in the same format as `core.whitespace` configuration
+	notice in the same format as the `core.whitespace` configuration
 	variable.
 
 

cache.h

@@ -1091,15 +1091,17 @@ void shift_tree_by(const unsigned char *, const unsigned char *, unsigned char *
 /*
  * whitespace rules.
  * used by both diff and apply
+ * last two digits are tab width
  */
-#define WS_BLANK_AT_EOL         01
-#define WS_SPACE_BEFORE_TAB	02
-#define WS_INDENT_WITH_NON_TAB	04
-#define WS_CR_AT_EOL           010
-#define WS_BLANK_AT_EOF        020
-#define WS_TAB_IN_INDENT       040
+#define WS_BLANK_AT_EOL         0100
+#define WS_SPACE_BEFORE_TAB     0200
+#define WS_INDENT_WITH_NON_TAB  0400
+#define WS_CR_AT_EOL           01000
+#define WS_BLANK_AT_EOF        02000
+#define WS_TAB_IN_INDENT       04000
 #define WS_TRAILING_SPACE      (WS_BLANK_AT_EOL|WS_BLANK_AT_EOF)
-#define WS_DEFAULT_RULE (WS_TRAILING_SPACE|WS_SPACE_BEFORE_TAB)
+#define WS_DEFAULT_RULE (WS_TRAILING_SPACE|WS_SPACE_BEFORE_TAB|8)
+#define WS_TAB_WIDTH_MASK        077
 extern unsigned whitespace_rule_cfg;
 extern unsigned whitespace_rule(const char *);
 extern unsigned parse_whitespace_rule(const char *);
@@ -1108,6 +1110,7 @@ extern void ws_check_emit(const char *line, int len, unsigned ws_rule, FILE *str
 extern char *whitespace_error_string(unsigned ws);
 extern void ws_fix_copy(struct strbuf *, const char *, int, unsigned, int *);
 extern int ws_blank_line(const char *line, int len, unsigned ws_rule);
+#define ws_tab_width(rule)     ((rule) & WS_TAB_WIDTH_MASK)
 
 /* ls-files */
 int report_path_error(const char *ps_matched, const char **pathspec, int prefix_offset);

t/t4015-diff-whitespace.sh

@@ -344,6 +344,13 @@ test_expect_success 'check spaces as indentation (indent-with-non-tab: on)' '
 
 '
 
+test_expect_success 'ditto, but tabwidth=9' '
+
+	git config core.whitespace "indent-with-non-tab,tabwidth=9" &&
+	git diff --check
+
+'
+
 test_expect_success 'check tabs and spaces as indentation (indent-with-non-tab: on)' '
 
 	git config core.whitespace "indent-with-non-tab" &&
@@ -352,6 +359,20 @@ test_expect_success 'check tabs and spaces as indentation (indent-with-non-tab:
 
 '
 
+test_expect_success 'ditto, but tabwidth=10' '
+
+	git config core.whitespace "indent-with-non-tab,tabwidth=10" &&
+	test_must_fail git diff --check
+
+'
+
+test_expect_success 'ditto, but tabwidth=20' '
+
+	git config core.whitespace "indent-with-non-tab,tabwidth=20" &&
+	git diff --check
+
+'
+
 test_expect_success 'check tabs as indentation (tab-in-indent: off)' '
 
 	git config core.whitespace "-tab-in-indent" &&
@@ -376,6 +397,13 @@ test_expect_success 'check tabs and spaces as indentation (tab-in-indent: on)' '
 
 '
 
+test_expect_success 'ditto, but tabwidth=1 (must be irrelevant)' '
+
+	git config core.whitespace "tab-in-indent,tabwidth=1" &&
+	test_must_fail git diff --check
+
+'
+
 test_expect_success 'check tab-in-indent and indent-with-non-tab conflict' '
 
 	git config core.whitespace "tab-in-indent,indent-with-non-tab" &&

t/t4019-diff-wserror.sh

@@ -51,8 +51,65 @@ test_expect_success default '
 
 '
 
+test_expect_success 'default (attribute)' '
+
+	test_might_fail git config --unset core.whitespace &&
+	echo "F whitespace" >.gitattributes &&
+	prepare_output &&
+
+	grep Eight error >/dev/null &&
+	grep HT error >/dev/null &&
+	grep With error >/dev/null &&
+	grep Return error >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
+test_expect_success 'default, tabwidth=10 (attribute)' '
+
+	git config core.whitespace "tabwidth=10" &&
+	echo "F whitespace" >.gitattributes &&
+	prepare_output &&
+
+	grep Eight normal >/dev/null &&
+	grep HT error >/dev/null &&
+	grep With error >/dev/null &&
+	grep Return error >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
+test_expect_success 'no check (attribute)' '
+
+	test_might_fail git config --unset core.whitespace &&
+	echo "F -whitespace" >.gitattributes &&
+	prepare_output &&
+
+	grep Eight normal >/dev/null &&
+	grep HT normal >/dev/null &&
+	grep With normal >/dev/null &&
+	grep Return normal >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
+test_expect_success 'no check, tabwidth=10 (attribute), must be irrelevant' '
+
+	git config core.whitespace "tabwidth=10" &&
+	echo "F -whitespace" >.gitattributes &&
+	prepare_output &&
+
+	grep Eight normal >/dev/null &&
+	grep HT normal >/dev/null &&
+	grep With normal >/dev/null &&
+	grep Return normal >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
 test_expect_success 'without -trail' '
 
+	rm -f .gitattributes &&
 	git config core.whitespace -trail &&
 	prepare_output &&
 
@@ -134,6 +191,34 @@ test_expect_success 'with indent-non-tab only (attribute)' '
 
 '
 
+test_expect_success 'with indent-non-tab only, tabwidth=10' '
+
+	rm -f .gitattributes &&
+	git config core.whitespace indent,tabwidth=10,-trailing,-space &&
+	prepare_output &&
+
+	grep Eight normal >/dev/null &&
+	grep HT normal >/dev/null &&
+	grep With normal >/dev/null &&
+	grep Return normal >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
+test_expect_success 'with indent-non-tab only, tabwidth=10 (attribute)' '
+
+	test_might_fail git config --unset core.whitespace &&
+	echo "F whitespace=indent,-trailing,-space,tabwidth=10" >.gitattributes &&
+	prepare_output &&
+
+	grep Eight normal >/dev/null &&
+	grep HT normal >/dev/null &&
+	grep With normal >/dev/null &&
+	grep Return normal >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
 test_expect_success 'with cr-at-eol' '
 
 	rm -f .gitattributes &&

t/t4124-apply-ws-rule.sh

@@ -10,7 +10,8 @@ prepare_test_file () {
 	#       X  RULE
 	#   	!  trailing-space
 	#   	@  space-before-tab
-	#   	#  indent-with-non-tab
+	#   	#  indent-with-non-tab (default tab width 8)
+	#	=  indent-with-non-tab,tabwidth=16
 	#   	%  tab-in-indent
 	sed -e "s/_/ /g" -e "s/>/	/" <<-\EOF
 		An_SP in an ordinary line>and a HT.
@@ -25,8 +26,8 @@ prepare_test_file () {
 		________>_Eight SP, a HT and a SP (@#%).
 		_______________Fifteen SP (#).
 		_______________>Fifteen SP and a HT (@#%).
-		________________Sixteen SP (#).
-		________________>Sixteen SP and a HT (@#%).
+		________________Sixteen SP (#=).
+		________________>Sixteen SP and a HT (@#%=).
 		_____a__Five SP, a non WS, two SP.
 		A line with a (!) trailing SP_
 		A line with a (!) trailing HT>
@@ -121,6 +122,34 @@ test_expect_success 'whitespace=error-all, no rule (attribute)' '
 
 '
 
+test_expect_success 'spaces inserted by tab-in-indent' '
+
+	git config core.whitespace -trailing,-space,-indent,tab &&
+	rm -f .gitattributes &&
+	test_fix % &&
+	sed -e "s/_/ /g" -e "s/>/	/" <<-\EOF >expect &&
+		An_SP in an ordinary line>and a HT.
+		________A HT (%).
+		________A SP and a HT (@%).
+		_________A SP, a HT and a SP (@%).
+		_______Seven SP.
+		________Eight SP (#).
+		________Seven SP and a HT (@%).
+		________________Eight SP and a HT (@#%).
+		_________Seven SP, a HT and a SP (@%).
+		_________________Eight SP, a HT and a SP (@#%).
+		_______________Fifteen SP (#).
+		________________Fifteen SP and a HT (@#%).
+		________________Sixteen SP (#=).
+		________________________Sixteen SP and a HT (@#%=).
+		_____a__Five SP, a non WS, two SP.
+		A line with a (!) trailing SP_
+		A line with a (!) trailing HT>
+	EOF
+	test_cmp expect target
+
+'
+
 for t in - ''
 do
 	case "$t" in '') tt='!' ;; *) tt= ;; esac
@@ -129,7 +158,7 @@ do
 		case "$s" in '') ts='@' ;; *) ts= ;; esac
 		for i in - ''
 		do
-			case "$i" in '') ti='#' ;; *) ti= ;; esac
+			case "$i" in '') ti='#' ti16='=';; *) ti= ti16= ;; esac
 			for h in - ''
 			do
 				[ -z "$h$i" ] && continue
@@ -142,12 +171,22 @@ do
 					test_fix "$tt$ts$ti$th"
 				'
 
+				test_expect_success "rule=$rule,tabwidth=16" '
+					git config core.whitespace "$rule,tabwidth=16" &&
+					test_fix "$tt$ts$ti16$th"
+				'
+
 				test_expect_success "rule=$rule (attributes)" '
 					git config --unset core.whitespace &&
 					echo "target whitespace=$rule" >.gitattributes &&
 					test_fix "$tt$ts$ti$th"
 				'
 
+				test_expect_success "rule=$rule,tabwidth=16 (attributes)" '
+					echo "target whitespace=$rule,tabwidth=16" >.gitattributes &&
+					test_fix "$tt$ts$ti16$th"
+				'
+
 			done
 		done
 	done

ws.c

@@ -56,6 +56,16 @@ unsigned parse_whitespace_rule(const char *string)
 				rule |= whitespace_rule_names[i].rule_bits;
 			break;
 		}
+		if (strncmp(string, "tabwidth=", 9) == 0) {
+			unsigned tabwidth = atoi(string + 9);
+			if (0 < tabwidth && tabwidth < 0100) {
+				rule &= ~WS_TAB_WIDTH_MASK;
+				rule |= tabwidth;
+			}
+			else
+				warning("tabwidth %.*s out of range",
+					(int)(len - 9), string + 9);
+		}
 		string = ep;
 	}
 
@@ -84,7 +94,7 @@ unsigned whitespace_rule(const char *pathname)
 		value = attr_whitespace_rule.value;
 		if (ATTR_TRUE(value)) {
 			/* true (whitespace) */
-			unsigned all_rule = 0;
+			unsigned all_rule = ws_tab_width(whitespace_rule_cfg);
 			int i;
 			for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
 				if (!whitespace_rule_names[i].loosens_error &&
@@ -93,7 +103,7 @@ unsigned whitespace_rule(const char *pathname)
 			return all_rule;
 		} else if (ATTR_FALSE(value)) {
 			/* false (-whitespace) */
-			return 0;
+			return ws_tab_width(whitespace_rule_cfg);
 		} else if (ATTR_UNSET(value)) {
 			/* reset to default (!whitespace) */
 			return whitespace_rule_cfg;
@@ -206,7 +216,7 @@ static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
 	}
 
 	/* Check for indent using non-tab. */
-	if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= 8) {
+	if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= ws_tab_width(ws_rule)) {
 		result |= WS_INDENT_WITH_NON_TAB;
 		if (stream) {
 			fputs(ws, stream);
@@ -320,7 +330,7 @@ void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule,
 		} else if (ch == ' ') {
 			last_space_in_indent = i;
 			if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
-			    8 <= i - last_tab_in_indent)
+			    ws_tab_width(ws_rule) <= i - last_tab_in_indent)
 				need_fix_leading_space = 1;
 		} else
 			break;
@@ -350,7 +360,7 @@ void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule,
 				strbuf_addch(dst, ch);
 			} else {
 				consecutive_spaces++;
-				if (consecutive_spaces == 8) {
+				if (consecutive_spaces == ws_tab_width(ws_rule)) {
 					strbuf_addch(dst, '\t');
 					consecutive_spaces = 0;
 				}
@@ -363,12 +373,13 @@ void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule,
 		fixed = 1;
 	} else if ((ws_rule & WS_TAB_IN_INDENT) && last_tab_in_indent >= 0) {
 		/* Expand tabs into spaces */
+		int start = dst->len;
 		int last = last_tab_in_indent + 1;
 		for (i = 0; i < last; i++) {
 			if (src[i] == '\t')
 				do {
 					strbuf_addch(dst, ' ');
-				} while (dst->len % 8);
+				} while ((dst->len - start) % ws_tab_width(ws_rule));
 			else
 				strbuf_addch(dst, src[i]);
 		}