libbb: move nuke_str() from passwd into libbb
[oweals/busybox.git] / editors / patch_toybox.c
index 0e5c070e202d0525d7e9b33511440c19a80dafce..a60bf070fc4a74db08c76245c0ffb9ebf09a64ec 100644 (file)
@@ -1,4 +1,4 @@
-/* Adapted from toybox's patch. Currently unused */
+/* Adapted from toybox's patch. */
 
 /* vi: set sw=4 ts=4:
  *
@@ -23,7 +23,7 @@
  * -F fuzz (number, default 2)
  * [file] which file to patch
 
-USE_PATCH(NEWTOY(patch, "up#i:R", TOYFLAG_USR|TOYFLAG_BIN))
+USE_PATCH(NEWTOY(patch, USE_TOYBOX_DEBUG("x")"up#i:R", TOYFLAG_USR|TOYFLAG_BIN))
 
 config PATCH
        bool "patch"
@@ -223,15 +223,16 @@ void delete_tempfile(int fdin, int fdout, char **tempname)
 
 
 struct globals {
-       struct double_list *plines;
-       long linenum;
-       int context;
-       int hunknum;
-       int filein;
-       int fileout;
-       int state;
+       char *infile;
+       long prefix;
+
+       struct double_list *current_hunk;
+       long oldline, oldlen, newline, newlen, linenum;
+       int context, state, filein, fileout, filepatch, hunknum;
        char *tempname;
-       smallint exitval;
+
+       // was toys.foo:
+       int exitval;
 };
 #define TT (*ptr_to_globals)
 #define INIT_TT() do { \
@@ -240,12 +241,14 @@ struct globals {
 
 
 //bbox had: "p:i:RN"
-#define FLAG_STR "Rup:i:"
+#define FLAG_STR "Rup:i:x"
 /* FLAG_REVERSE must be == 1! Code uses this fact. */
 #define FLAG_REVERSE (1 << 0)
 #define FLAG_u       (1 << 1)
 #define FLAG_PATHLEN (1 << 2)
 #define FLAG_INPUT   (1 << 3)
+//non-standard:
+#define FLAG_DEBUG   (1 << 4)
 
 // Dispose of a line of input, either by writing it out or discarding it.
 
@@ -254,6 +257,8 @@ struct globals {
 // state = 3: write whole line to fileout
 // state > 3: write line+1 to fileout when *line != state
 
+#define PATCH_DEBUG (option_mask32 & FLAG_DEBUG)
+
 static void do_line(void *data)
 {
        struct double_list *dlist = (struct double_list *)data;
@@ -262,6 +267,8 @@ static void do_line(void *data)
                fdprintf(TT.state == 2 ? 2 : TT.fileout,
                        "%s\n", dlist->data+(TT.state>3 ? 1 : 0));
 
+       if (PATCH_DEBUG) fdprintf(2, "DO %d: %s\n", TT.state, dlist->data);
+
        free(dlist->data);
        free(data);
 }
@@ -274,94 +281,118 @@ static void finish_oldfile(void)
 
 static void fail_hunk(void)
 {
-       if (!TT.plines) return;
-       TT.plines->prev->next = 0;
+       if (!TT.current_hunk) return;
+       TT.current_hunk->prev->next = 0;
 
-       fdprintf(2, "Hunk %d FAILED.\n", TT.hunknum);
+       fdprintf(2, "Hunk %d FAILED %ld/%ld.\n", TT.hunknum, TT.oldline, TT.newline);
        TT.exitval = 1;
 
        // If we got to this point, we've seeked to the end.  Discard changes to
        // this file and advance to next file.
 
        TT.state = 2;
-       TOY_llist_free(TT.plines, do_line);
-       TT.plines = NULL;
+       TOY_llist_free(TT.current_hunk, do_line);
+       TT.current_hunk = NULL;
        delete_tempfile(TT.filein, TT.fileout, &TT.tempname);
        TT.state = 0;
 }
 
-static int apply_hunk(void)
+// Given a hunk of a unified diff, make the appropriate change to the file.
+// This does not use the location information, but instead treats a hunk
+// as a sort of regex.  Copies data from input to output until it finds
+// the change to be made, then outputs the changed data and returns.
+// (Finding EOF first is an error.)  This is a single pass operation, so
+// multiple hunks must occur in order in the file.
+
+static int apply_one_hunk(void)
 {
        struct double_list *plist, *buf = NULL, *check;
-       int i = 0, backwards = 0, matcheof = 0,
-               reverse = option_mask32 & FLAG_REVERSE;
+       int matcheof = 0, reverse = option_mask32 & FLAG_REVERSE, backwarn = 0;
 
        // Break doubly linked list so we can use singly linked traversal function.
-       TT.plines->prev->next = NULL;
+       TT.current_hunk->prev->next = NULL;
 
        // Match EOF if there aren't as many ending context lines as beginning
-       for (plist = TT.plines; plist; plist = plist->next) {
-               if (plist->data[0]==' ') i++;
-               else i = 0;
+       for (plist = TT.current_hunk; plist; plist = plist->next) {
+               if (plist->data[0]==' ') matcheof++;
+               else matcheof = 0;
+               if (PATCH_DEBUG) fdprintf(2, "HUNK:%s\n", plist->data);
        }
-       if (i < TT.context) matcheof++;
+       matcheof = matcheof < TT.context;
 
-       // Search for a place to apply this hunk.  Match all context lines and
-       // lines to be removed.
-       plist = TT.plines;
-       buf = NULL;
-       i = 0;
+       if (PATCH_DEBUG) fdprintf(2,"MATCHEOF=%c\n", matcheof ? 'Y' : 'N');
 
-       // Start of for loop
+       // Loop through input data searching for this hunk.  Match all context
+       // lines and all lines to be removed until we've found the end of a
+       // complete hunk.
+       plist = TT.current_hunk;
+       buf = NULL;
        if (TT.context) for (;;) {
                char *data = get_line(TT.filein);
 
                TT.linenum++;
 
-               // Skip lines of the hunk we'd be adding.
+               // Figure out which line of hunk to compare with next.  (Skip lines
+               // of the hunk we'd be adding.)
                while (plist && *plist->data == "+-"[reverse]) {
                        if (data && !strcmp(data, plist->data+1)) {
-                               if (++backwards == TT.context)
+                               if (!backwarn) {
                                        fdprintf(2,"Possibly reversed hunk %d at %ld\n",
                                                TT.hunknum, TT.linenum);
-                       } else backwards=0;
+                                       backwarn++;
+                               }
+                       }
                        plist = plist->next;
                }
 
                // Is this EOF?
                if (!data) {
+                       if (PATCH_DEBUG) fdprintf(2, "INEOF\n");
+
                        // Does this hunk need to match EOF?
                        if (!plist && matcheof) break;
 
                        // File ended before we found a place for this hunk.
                        fail_hunk();
                        goto done;
-               }
+               } else if (PATCH_DEBUG) fdprintf(2, "IN: %s\n", data);
                check = dlist_add(&buf, data);
 
+               // Compare this line with next expected line of hunk.
                // todo: teach the strcmp() to ignore whitespace.
 
-               for (;;) {
-                       // If we hit the end of a hunk that needed EOF and this isn't EOF,
-                       // or next line doesn't match, flush first line of buffered data and
-                       // recheck match until we find a new match or run out of buffer.
+               // A match can fail because the next line doesn't match, or because
+               // we hit the end of a hunk that needed EOF, and this isn't EOF.
+
+               // If match failed, flush first line of buffered data and
+               // recheck buffered data for a new match until we find one or run
+               // out of buffer.
 
+               for (;;) {
                        if (!plist || strcmp(check->data, plist->data+1)) {
-                               // First line isn't a match, write it out.
+                               // Match failed.  Write out first line of buffered data and
+                               // recheck remaining buffered data for a new match.
+
+                               if (PATCH_DEBUG)
+                                       fdprintf(2, "NOT: %s\n", plist->data);
+
                                TT.state = 3;
                                check = TOY_llist_pop(&buf);
                                check->prev->next = buf;
                                buf->prev = check->prev;
                                do_line(check);
-                               plist = TT.plines;
+                               plist = TT.current_hunk;
 
-                               // Out of buffered lines?
+                               // If we've reached the end of the buffer without confirming a
+                               // match, read more lines.
                                if (check==buf) {
                                        buf = 0;
                                        break;
                                }
                                check = buf;
                        } else {
+                               if (PATCH_DEBUG)
+                                       fdprintf(2, "MAYBE: %s\n", plist->data);
                                // This line matches.  Advance plist, detect successful match.
                                plist = plist->next;
                                if (!plist && !matcheof) goto out;
@@ -371,10 +402,10 @@ static int apply_hunk(void)
                }
        }
 out:
-       // Got it.  Emit changed data.
+       // We have a match.  Emit changed data.
        TT.state = "-+"[reverse];
-       TOY_llist_free(TT.plines, do_line);
-       TT.plines = NULL;
+       TOY_llist_free(TT.current_hunk, do_line);
+       TT.current_hunk = NULL;
        TT.state = 1;
 done:
        if (buf) {
@@ -385,6 +416,9 @@ done:
        return TT.state;
 }
 
+// Read a patch file and find hunks, opening/creating/deleting files.
+// Call apply_one_hunk() on each hunk.
+
 // state 0: Not in a hunk, look for +++.
 // state 1: Found +++ file indicator, look for @@
 // state 2: In hunk: counting initial context lines
@@ -397,24 +431,20 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
        int reverse, state = 0;
        char *oldname = NULL, *newname = NULL;
        char *opt_p, *opt_i;
-       int prefix;
-
-       long oldline = 0, oldlen = 0, newline = 0, newlen = 0;
 
        INIT_TT();
 
        opts = getopt32(argv, FLAG_STR, &opt_p, &opt_i);
        reverse = opts & FLAG_REVERSE;
-
-       if (opts & FLAG_INPUT) xmove_fd(xopen(opt_i, O_RDONLY), STDIN_FILENO);
-       prefix = (opts & FLAG_PATHLEN) ? xatoi(opt_p) : 0; // can be negative!
+       TT.prefix = (opts & FLAG_PATHLEN) ? xatoi(opt_p) : 0; // can be negative!
+       if (opts & FLAG_INPUT) TT.filepatch = xopen(opt_i, O_RDONLY);
        TT.filein = TT.fileout = -1;
 
        // Loop through the lines in the patch
        for(;;) {
                char *patchline;
 
-               patchline = get_line(STDIN_FILENO);
+               patchline = get_line(TT.filepatch);
                if (!patchline) break;
 
                // Other versions of patch accept damaged patches,
@@ -427,17 +457,18 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                // Are we assembling a hunk?
                if (state >= 2) {
                        if (*patchline==' ' || *patchline=='+' || *patchline=='-') {
-                               dlist_add(&TT.plines, patchline);
+                               dlist_add(&TT.current_hunk, patchline);
 
-                               if (*patchline != '+') oldlen--;
-                               if (*patchline != '-') newlen--;
+                               if (*patchline != '+') TT.oldlen--;
+                               if (*patchline != '-') TT.newlen--;
 
                                // Context line?
                                if (*patchline==' ' && state==2) TT.context++;
                                else state=3;
 
                                // If we've consumed all expected hunk lines, apply the hunk.
-                               if (!oldlen && !newlen) state = apply_hunk();
+
+                               if (!TT.oldlen && !TT.newlen) state = apply_one_hunk();
                                continue;
                        }
                        fail_hunk();
@@ -447,11 +478,11 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
 
                // Open a new file?
                if (!strncmp("--- ", patchline, 4) || !strncmp("+++ ", patchline, 4)) {
-                       char *s, **name = &oldname;
+                       char *s, **name = reverse ? &newname : &oldname;
                        int i;
 
                        if (*patchline == '+') {
-                               name = &newname;
+                               name = reverse ? &oldname : &newname;
                                state = 1;
                        }
 
@@ -462,7 +493,7 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                        for (s = patchline+4; *s && *s!='\t'; s++)
                                if (*s=='\\' && s[1]) s++;
                        i = atoi(s);
-                       if (i && i<=1970)
+                       if (i>1900 && i<=1970)
                                *name = xstrdup("/dev/null");
                        else {
                                *s = 0;
@@ -478,8 +509,8 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                } else if (state == 1 && !strncmp("@@ -", patchline, 4)) {
                        int i;
 
-                       i = sscanf(patchline+4, "%ld,%ld +%ld,%ld",
-                                       &oldline, &oldlen, &newline, &newlen);
+                       i = sscanf(patchline+4, "%ld,%ld +%ld,%ld", &TT.oldline,
+                                               &TT.oldlen, &TT.newline, &TT.newlen);
                        if (i != 4)
                                bb_error_msg_and_die("corrupt hunk %d at %ld", TT.hunknum, TT.linenum);
 
@@ -491,22 +522,22 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                                int oldsum, newsum, del = 0;
                                char *s, *name;
 
-                               oldsum = oldline + oldlen;
-                               newsum = newline + newlen;
+                               oldsum = TT.oldline + TT.oldlen;
+                               newsum = TT.newline + TT.newlen;
 
                                name = reverse ? oldname : newname;
 
                                // We're deleting oldname if new file is /dev/null (before -p)
                                // or if new hunk is empty (zero context) after patching
-                               if (!strcmp(name, "/dev/null") || !(reverse ? oldsum : newsum)) {
+                               if (!strcmp(name, "/dev/null") || !(reverse ? oldsum : newsum))
+                               {
                                        name = reverse ? newname : oldname;
                                        del++;
                                }
 
                                // handle -p path truncation.
                                for (i=0, s = name; *s;) {
-                                       if ((option_mask32 & FLAG_PATHLEN) && prefix == i)
-                                               break;
+                                       if ((option_mask32 & FLAG_PATHLEN) && TT.prefix == i) break;
                                        if (*(s++)=='/') {
                                                name = s;
                                                i++;
@@ -518,7 +549,7 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                                        xunlink(name);
                                        state = 0;
                                // If we've got a file to open, do so.
-                               } else if (!(option_mask32 & FLAG_PATHLEN) || i <= prefix) {
+                               } else if (!(option_mask32 & FLAG_PATHLEN) || i <= TT.prefix) {
                                        // If the old file was null, we're creating a new one.
                                        if (!strcmp(oldname, "/dev/null") || !oldsum) {
                                                printf("creating %s\n", name);
@@ -528,7 +559,7 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                                                        xmkpath(name, -1);
                                                        *s = '/';
                                                }
-                                               TT.filein = xopen3(name, O_CREAT|O_EXCL|O_RDWR, 0666);
+                                               TT.filein = xopen(name, O_CREAT|O_EXCL|O_RDWR);
                                        } else {
                                                printf("patching file %s\n", name);
                                                TT.filein = xopen(name, O_RDWR);
@@ -551,6 +582,7 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
        finish_oldfile();
 
        if (ENABLE_FEATURE_CLEAN_UP) {
+               close(TT.filepatch);
                free(oldname);
                free(newname);
        }