git-apply: second war on whitespace.

This makes --whitespace={warn,error,strip} option to also notice
the leading whitespace errors in addition to the trailing
whitespace errors.  Spaces that are followed by a tab in indent
are detected as errors, and --whitespace=strip option fixes them.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/builtin-apply.c b/builtin-apply.c
index 25e90d8d29a8f55b20a98425edccfe49cad4c8e2..de5f855266f6fcf3274c9648b02ab960a267bb90 100644 (file)
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -854,6 +854,49 @@ static int find_header(char *line, unsigned long size, int *hdrsize, struct patc
        return -1;
 }
 
+static void check_whitespace(const char *line, int len)
+{
+       const char *err = "Adds trailing whitespace";
+       int seen_space = 0;
+       int i;
+
+       /*
+        * We know len is at least two, since we have a '+' and we
+        * checked that the last character was a '\n' before calling
+        * this function.  That is, an addition of an empty line would
+        * check the '+' here.  Sneaky...
+        */
+       if (isspace(line[len-2]))
+               goto error;
+
+       /*
+        * Make sure that there is no space followed by a tab in
+        * indentation.
+        */
+       err = "Space in indent is followed by a tab";
+       for (i = 1; i < len; i++) {
+               if (line[i] == '\t') {
+                       if (seen_space)
+                               goto error;
+               }
+               else if (line[i] == ' ')
+                       seen_space = 1;
+               else
+                       break;
+       }
+       return;
+
+ error:
+       whitespace_error++;
+       if (squelch_whitespace_errors &&
+           squelch_whitespace_errors < whitespace_error)
+               ;
+       else
+               fprintf(stderr, "%s.\n%s:%d:%.*s\n",
+                       err, patch_input_file, linenr, len-2, line+1);
+}
+
+
 /*
  * Parse a unified diff. Note that this really needs to parse each
  * fragment separately, since the only way to know the difference
@@ -904,25 +947,8 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
                        trailing = 0;
                        break;
                case '+':
-                       /*
-                        * We know len is at least two, since we have a '+' and
-                        * we checked that the last character was a '\n' above.
-                        * That is, an addition of an empty line would check
-                        * the '+' here.  Sneaky...
-                        */
-                       if ((new_whitespace != nowarn_whitespace) &&
-                           isspace(line[len-2])) {
-                               whitespace_error++;
-                               if (squelch_whitespace_errors &&
-                                   squelch_whitespace_errors <
-                                   whitespace_error)
-                                       ;
-                               else {
-                                       fprintf(stderr, "Adds trailing whitespace.\n%s:%d:%.*s\n",
-                                               patch_input_file,
-                                               linenr, len-2, line+1);
-                               }
-                       }
+                       if (new_whitespace != nowarn_whitespace)
+                               check_whitespace(line, len);
                        added++;
                        newlines--;
                        trailing = 0;
@@ -1494,22 +1520,68 @@ static int apply_line(char *output, const char *patch, int plen)
 {
        /* plen is number of bytes to be copied from patch,
         * starting at patch+1 (patch[0] is '+').  Typically
-        * patch[plen] is '\n'.
+        * patch[plen] is '\n', unless this is the incomplete
+        * last line.
         */
+       int i;
        int add_nl_to_tail = 0;
-       if ((new_whitespace == strip_whitespace) &&
-           1 < plen && isspace(patch[plen-1])) {
+       int fixed = 0;
+       int last_tab_in_indent = -1;
+       int last_space_in_indent = -1;
+       int need_fix_leading_space = 0;
+       char *buf;
+
+       if ((new_whitespace != strip_whitespace) || !whitespace_error) {
+               memcpy(output, patch + 1, plen);
+               return plen;
+       }
+
+       if (1 < plen && isspace(patch[plen-1])) {
                if (patch[plen] == '\n')
                        add_nl_to_tail = 1;
                plen--;
                while (0 < plen && isspace(patch[plen]))
                        plen--;
-               applied_after_stripping++;
+               fixed = 1;
        }
-       memcpy(output, patch + 1, plen);
+
+       for (i = 1; i < plen; i++) {
+               char ch = patch[i];
+               if (ch == '\t') {
+                       last_tab_in_indent = i;
+                       if (0 <= last_space_in_indent)
+                               need_fix_leading_space = 1;
+               }
+               else if (ch == ' ')
+                       last_space_in_indent = i;
+               else
+                       break;
+       }
+
+       buf = output;
+       if (need_fix_leading_space) {
+               /* between patch[1..last_tab_in_indent] strip the
+                * funny spaces, updating them to tab as needed.
+                */
+               for (i = 1; i < last_tab_in_indent; i++, plen--) {
+                       char ch = patch[i];
+                       if (ch != ' ')
+                               *output++ = ch;
+                       else if ((i % 8) == 0)
+                               *output++ = '\t';
+               }
+               fixed = 1;
+               i = last_tab_in_indent;
+       }
+       else
+               i = 1;
+
+       memcpy(output, patch + i, plen);
        if (add_nl_to_tail)
                output[plen++] = '\n';
-       return plen;
+       if (fixed)
+               applied_after_stripping++;
+       return output + plen - buf;
 }
 
 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag, int inaccurate_eof)