diff --color-moved-ws: handle blank lines

[thirdparty/git.git] / diff.c

diff --git a/diff.c b/diff.c
index 941956d8c4b4ea00b86deee3a7b3004570109b87..03ffe467e474cf4ecef31cacb3f81a0ba8160fae 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -794,9 +794,11 @@ static void moved_block_clear(struct moved_block *b)
        memset(b, 0, sizeof(*b));
 }
 
+#define INDENT_BLANKLINE INT_MIN
+
 static void fill_es_indent_data(struct emitted_diff_symbol *es)
 {
-       unsigned int off = 0;
+       unsigned int off = 0, i;
        int width = 0, tab_width = es->flags & WS_TAB_WIDTH_MASK;
        const char *s = es->line;
        const int len = es->len;
@@ -820,8 +822,18 @@ static void fill_es_indent_data(struct emitted_diff_symbol *es)
                }
        }
 
-       es->indent_off = off;
-       es->indent_width = width;
+       /* check if this line is blank */
+       for (i = off; i < len; i++)
+               if (!isspace(s[i]))
+                   break;
+
+       if (i == len) {
+               es->indent_width = INDENT_BLANKLINE;
+               es->indent_off = len;
+       } else {
+               es->indent_off = off;
+               es->indent_width = width;
+       }
 }
 
 static int compute_ws_delta(const struct emitted_diff_symbol *a,
@@ -836,6 +848,11 @@ static int compute_ws_delta(const struct emitted_diff_symbol *a,
            b_width = b->indent_width;
        int delta;
 
+       if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
+               *out = INDENT_BLANKLINE;
+               return 1;
+       }
+
        if (a->s == DIFF_SYMBOL_PLUS)
                delta = a_width - b_width;
        else
@@ -879,6 +896,10 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
        if (al != bl)
                return 1;
 
+       /* If 'l' and 'cur' are both blank then they match. */
+       if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
+               return 0;
+
        /*
         * The indent changes of the block are known and stored in pmb->wsd;
         * however we need to check if the indent changes of the current line
@@ -890,6 +911,13 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
        else
                delta = c_width - a_width;
 
+       /*
+        * If the previous lines of this block were all blank then set its
+        * whitespace delta.
+        */
+       if (pmb->wsd == INDENT_BLANKLINE)
+               pmb->wsd = delta;
+
        return !(delta == pmb->wsd && al - a_off == cl - c_off &&
                 !memcmp(a, b, al) && !
                 memcmp(a + a_off, c + c_off, al - a_off));