War on whitespace: first, a bit of retreat.

This introduces core.whitespace configuration variable that lets
you specify the definition of "whitespace error".

Currently there are two kinds of whitespace errors defined:

 * trailing-space: trailing whitespaces at the end of the line.

 * space-before-tab: a SP appears immediately before HT in the
   indent part of the line.

You can specify the desired types of errors to be detected by
listing their names (unique abbreviations are accepted)
separated by comma.  By default, these two errors are always
detected, as that is the traditional behaviour.  You can disable
detection of a particular type of error by prefixing a '-' in
front of the name of the error, like this:

	[core]
		whitespace = -trailing-space

This patch teaches the code to output colored diff with
DIFF_WHITESPACE color to highlight the detected whitespace
errors to honor the new configuration.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/cache.h b/cache.h
index bfffa05dff149a948e46b04f6b15589e6f4be07e..a6e5988f0778803f11de7b7b440e15f75372d6de 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -602,4 +602,13 @@ extern int diff_auto_refresh_index;
 /* match-trees.c */
 void shift_tree(const unsigned char *, const unsigned char *, unsigned char *, int);
 
+/*
+ * whitespace rules.
+ * used by both diff and apply
+ */
+#define WS_TRAILING_SPACE      01
+#define WS_SPACE_BEFORE_TAB    02
+#define WS_DEFAULT_RULE (WS_TRAILING_SPACE|WS_SPACE_BEFORE_TAB)
+extern unsigned whitespace_rule;
+
 #endif /* CACHE_H */

diff --git a/config.c b/config.c
index dc3148d4566205858869973804de1c2ddb19e981..ffb418ccffc751ef87d8534264fa56b1ca8a6683 100644 (file)
--- a/config.c
+++ b/config.c
@@ -246,6 +246,53 @@ static unsigned long get_unit_factor(const char *end)
        die("unknown unit: '%s'", end);
 }
 
+static struct whitespace_rule {
+       const char *rule_name;
+       unsigned rule_bits;
+} whitespace_rule_names[] = {
+       { "trailing-space", WS_TRAILING_SPACE },
+       { "space-before-tab", WS_SPACE_BEFORE_TAB },
+};
+
+static unsigned parse_whitespace_rule(const char *string)
+{
+       unsigned rule = WS_DEFAULT_RULE;
+
+       while (string) {
+               int i;
+               size_t len;
+               const char *ep;
+               int negated = 0;
+
+               string = string + strspn(string, ", \t\n\r");
+               ep = strchr(string, ',');
+               if (!ep)
+                       len = strlen(string);
+               else
+                       len = ep - string;
+
+               if (*string == '-') {
+                       negated = 1;
+                       string++;
+                       len--;
+               }
+               if (!len)
+                       break;
+               for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
+                       if (strncmp(whitespace_rule_names[i].rule_name,
+                                   string, len))
+                               continue;
+                       if (negated)
+                               rule &= ~whitespace_rule_names[i].rule_bits;
+                       else
+                               rule |= whitespace_rule_names[i].rule_bits;
+                       break;
+               }
+               string = ep;
+       }
+       return rule;
+}
+
 int git_parse_long(const char *value, long *ret)
 {
        if (value && *value) {
@@ -431,6 +478,11 @@ int git_default_config(const char *var, const char *value)
                return 0;
        }
 
+       if (!strcmp(var, "core.whitespace")) {
+               whitespace_rule = parse_whitespace_rule(value);
+               return 0;
+       }
+
        /* Add other config variables here and to Documentation/config.txt. */
        return 0;
 }

diff --git a/diff.c b/diff.c
index a6aaaf7e5a91f3e5ad5f85341429c80a3452504e..211235376de2166593945a646dcfa97405dc74d0 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -508,7 +508,8 @@ static void emit_line_with_ws(int nparents,
        for (i = col0; i < len; i++) {
                if (line[i] == '\t') {
                        last_tab_in_indent = i;
-                       if (0 <= last_space_in_indent)
+                       if ((whitespace_rule & WS_SPACE_BEFORE_TAB) &&
+                           0 <= last_space_in_indent)
                                need_highlight_leading_space = 1;
                }
                else if (line[i] == ' ')
@@ -540,10 +541,12 @@ static void emit_line_with_ws(int nparents,
        tail = len - 1;
        if (line[tail] == '\n' && i < tail)
                tail--;
-       while (i < tail) {
-               if (!isspace(line[tail]))
-                       break;
-               tail--;
+       if (whitespace_rule & WS_TRAILING_SPACE) {
+               while (i < tail) {
+                       if (!isspace(line[tail]))
+                               break;
+                       tail--;
+               }
        }
        if ((i < tail && line[tail + 1] != '\n')) {
                /* This has whitespace between tail+1..len */

diff --git a/environment.c b/environment.c
index b5a6c69f7c1d214daa2556d04dd35e0976fc6e5e..624dd9677ce0a6d8d23973683d62ce83f61f02fe 100644 (file)
--- a/environment.c
+++ b/environment.c
@@ -35,6 +35,7 @@ int pager_in_use;
 int pager_use_color = 1;
 char *editor_program;
 int auto_crlf = 0;     /* 1: both ways, -1: only when adding git objects */
+unsigned whitespace_rule = WS_DEFAULT_RULE;
 
 /* This is set by setup_git_dir_gently() and/or git_default_config() */
 char *git_work_tree_cfg;