patch: fix "patch at the beginning" testcase failure

Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 14 insertions, 9 deletions

diff --git a/editors/patch.c b/editors/patch.c
index 1d4a2554e..9c6d967b9 100644
--- a/editors/patch.c
+++ b/editors/patch.c
@@ -238,7 +238,7 @@ static int apply_one_hunk(void)
         // complete hunk.
         plist = TT.current_hunk;
         buf = NULL;
-        if (TT.context) for (;;) {
+        if (reverse ? TT.oldlen : TT.newlen) for (;;) {
                 char *data = xmalloc_reads(TT.filein, NULL, NULL);
 
                 TT.linenum++;
@@ -352,6 +352,8 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
         int reverse, state = 0;
         char *oldname = NULL, *newname = NULL;
         char *opt_p, *opt_i;
+        long oldlen = oldlen; /* for compiler */
+        long newlen = newlen; /* for compiler */
 
         INIT_TT();
 
@@ -391,8 +393,8 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                         if (*patchline==' ' || *patchline=='+' || *patchline=='-') {
                                 dlist_add(&TT.current_hunk, patchline);
 
-                                if (*patchline != '+') TT.oldlen--;
-                                if (*patchline != '-') TT.newlen--;
+                                if (*patchline != '+') oldlen--;
+                                if (*patchline != '-') newlen--;
 
                                 // Context line?
                                 if (*patchline==' ' && state==2) TT.context++;
@@ -400,7 +402,7 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
 
                                 // If we've consumed all expected hunk lines, apply the hunk.
 
-                                if (!TT.oldlen && !TT.newlen) state = apply_one_hunk();
+                                if (!oldlen && !newlen) state = apply_one_hunk();
                                 continue;
                         }
                         fail_hunk();
@@ -447,11 +449,14 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
 
                         // Read oldline[,oldlen] +newline[,newlen]
 
-                        TT.oldlen = TT.newlen = 1;
+                        TT.oldlen = oldlen = TT.newlen = newlen = 1;
                         TT.oldline = strtol(s, &s, 10);
-                        if (*s == ',') TT.oldlen=strtol(s+1, &s, 10);
+                        if (*s == ',') TT.oldlen = oldlen = strtol(s+1, &s, 10);
                         TT.newline = strtol(s+2, &s, 10);
-                        if (*s == ',') TT.newlen = strtol(s+1, &s, 10);
+                        if (*s == ',') TT.newlen = newlen = strtol(s+1, &s, 10);
+
+                        if (oldlen < 1 && newlen < 1)
+                                bb_error_msg_and_die("Really? %s", patchline);
 
                         TT.context = 0;
                         state = 2;
@@ -461,8 +466,8 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                                 int oldsum, newsum, empty = 0;
                                 char *name;
 
-                                oldsum = TT.oldline + TT.oldlen;
-                                newsum = TT.newline + TT.newlen;
+                                oldsum = TT.oldline + oldlen;
+                                newsum = TT.newline + newlen;
 
                                 name = reverse ? oldname : newname;