Fix gitmkdtemp: correct test for mktemp() return value

[git.git] / xdiff-interface.c

diff --git a/xdiff-interface.c b/xdiff-interface.c
index be866d12d38f6f1328f5fae8c7108176d4ecba70..3bf83f81e38d4a4cc114f3c577241cf7b9eddc7e 100644 (file)
--- a/xdiff-interface.c
+++ b/xdiff-interface.c
@@ -103,6 +103,44 @@ int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
        return 0;
 }
 
+/*
+ * Trim down common substring at the end of the buffers,
+ * but leave at least ctx lines at the end.
+ */
+static void trim_common_tail(mmfile_t *a, mmfile_t *b, long ctx)
+{
+       const int blk = 1024;
+       long trimmed = 0, recovered = 0;
+       char *ap = a->ptr + a->size;
+       char *bp = b->ptr + b->size;
+       long smaller = (a->size < b->size) ? a->size : b->size;
+
+       if (ctx)
+               return;
+
+       while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
+               trimmed += blk;
+               ap -= blk;
+               bp -= blk;
+       }
+
+       while (recovered < trimmed)
+               if (ap[recovered++] == '\n')
+                       break;
+       a->size -= trimmed - recovered;
+       b->size -= trimmed - recovered;
+}
+
+int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
+{
+       mmfile_t a = *mf1;
+       mmfile_t b = *mf2;
+
+       trim_common_tail(&a, &b, xecfg->ctxlen);
+
+       return xdl_diff(&a, &b, xpp, xecfg, xecb);
+}
+
 int read_mmfile(mmfile_t *ptr, const char *filename)
 {
        struct stat st;
@@ -114,8 +152,8 @@ int read_mmfile(mmfile_t *ptr, const char *filename)
        if ((f = fopen(filename, "rb")) == NULL)
                return error("Could not open %s", filename);
        sz = xsize_t(st.st_size);
-       ptr->ptr = xmalloc(sz);
-       if (fread(ptr->ptr, sz, 1, f) != 1)
+       ptr->ptr = xmalloc(sz ? sz : 1);
+       if (sz && fread(ptr->ptr, sz, 1, f) != 1)
                return error("Could not read %s", filename);
        fclose(f);
        ptr->size = sz;
@@ -141,11 +179,21 @@ struct ff_regs {
 static long ff_regexp(const char *line, long len,
                char *buffer, long buffer_size, void *priv)
 {
-       char *line_buffer = xstrndup(line, len); /* make NUL terminated */
+       char *line_buffer;
        struct ff_regs *regs = priv;
        regmatch_t pmatch[2];
        int result = 0, i;
 
+       /* Exclude terminating newline (and cr) from matching */
+       if (len > 0 && line[len-1] == '\n') {
+               if (len > 1 && line[len-2] == '\r')
+                       len -= 2;
+               else
+                       len--;
+       }
+
+       line_buffer = xstrndup(line, len); /* make NUL terminated */
+
        for (i = 0; i < regs->nr; i++) {
                struct ff_reg *reg = regs->array + i;
                if (reg->negate ^ !!regexec(&reg->re,
@@ -168,7 +216,7 @@ static long ff_regexp(const char *line, long len,
        return result;
 }
 
-void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value)
+void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
 {
        int i;
        struct ff_regs *regs;
@@ -193,10 +241,9 @@ void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value)
                        expression = buffer = xstrndup(value, ep - value);
                else
                        expression = value;
-               if (regcomp(&reg->re, expression, 0))
+               if (regcomp(&reg->re, expression, cflags))
                        die("Invalid regexp to look for hunk header: %s", expression);
-               if (buffer)
-                       free(buffer);
+               free(buffer);
                value = ep + 1;
        }
 }