1 files changed, 39 insertions, 29 deletions

diff --git a/src/backend/snowball/libstemmer/utilities.c b/src/backend/snowball/libstemmer/utilities.c
index 681bca09c2f..1ecd2410fe7 100644
--- a/src/backend/snowball/libstemmer/utilities.c
+++ b/src/backend/snowball/libstemmer/utilities.c
@@ -18,38 +18,48 @@ extern void lose_s(symbol * p) {
 }
 
 /*
-   new_p = skip_utf8(p, c, lb, l, n); skips n characters forwards from p + c
-   if n +ve, or n characters backwards from p + c - 1 if n -ve. new_p is the new
-   position, or -1 on failure.
+   new_p = skip_utf8(p, c, l, n); skips n characters forwards from p + c.
+   new_p is the new position, or -1 on failure.
 
    -- used to implement hop and next in the utf8 case.
 */
 
-extern int skip_utf8(const symbol * p, int c, int lb, int l, int n) {
+extern int skip_utf8(const symbol * p, int c, int limit, int n) {
     int b;
-    if (n >= 0) {
-        for (; n > 0; n--) {
-            if (c >= l) return -1;
-            b = p[c++];
-            if (b >= 0xC0) {   /* 1100 0000 */
-                while (c < l) {
-                    b = p[c];
-                    if (b >= 0xC0 || b < 0x80) break;
-                    /* break unless b is 10------ */
-                    c++;
-                }
+    if (n < 0) return -1;
+    for (; n > 0; n--) {
+        if (c >= limit) return -1;
+        b = p[c++];
+        if (b >= 0xC0) {   /* 1100 0000 */
+            while (c < limit) {
+                b = p[c];
+                if (b >= 0xC0 || b < 0x80) break;
+                /* break unless b is 10------ */
+                c++;
             }
         }
-    } else {
-        for (; n < 0; n++) {
-            if (c <= lb) return -1;
-            b = p[--c];
-            if (b >= 0x80) {   /* 1000 0000 */
-                while (c > lb) {
-                    b = p[c];
-                    if (b >= 0xC0) break; /* 1100 0000 */
-                    c--;
-                }
+    }
+    return c;
+}
+
+/*
+   new_p = skip_b_utf8(p, c, lb, n); skips n characters backwards from p + c - 1
+   new_p is the new position, or -1 on failure.
+
+   -- used to implement hop and next in the utf8 case.
+*/
+
+extern int skip_b_utf8(const symbol * p, int c, int limit, int n) {
+    int b;
+    if (n < 0) return -1;
+    for (; n > 0; n--) {
+        if (c <= limit) return -1;
+        b = p[--c];
+        if (b >= 0x80) {   /* 1000 0000 */
+            while (c > limit) {
+                b = p[c];
+                if (b >= 0xC0) break; /* 1100 0000 */
+                c--;
             }
         }
     }
@@ -76,7 +86,7 @@ static int get_utf8(const symbol * p, int c, int l, int * slot) {
         *slot = (b0 & 0xF) << 12 | b1 << 6 | b2;
         return 3;
     }
-    *slot = (b0 & 0xE) << 18 | b1 << 12 | b2 << 6 | (p[c] & 0x3F);
+    *slot = (b0 & 0x7) << 18 | b1 << 12 | b2 << 6 | (p[c] & 0x3F);
     return 4;
 }
 
@@ -100,7 +110,7 @@ static int get_b_utf8(const symbol * p, int c, int lb, int * slot) {
         *slot = (b & 0xF) << 12 | a;
         return 3;
     }
-    *slot = (p[--c] & 0xE) << 18 | (b & 0x3F) << 12 | a;
+    *slot = (p[--c] & 0x7) << 18 | (b & 0x3F) << 12 | a;
     return 4;
 }
 
@@ -226,7 +236,7 @@ extern int find_among(struct SN_env * z, const struct among * v, int v_size) {
     int j = v_size;
 
     int c = z->c; int l = z->l;
-    symbol * q = z->p + c;
+    const symbol * q = z->p + c;
 
     const struct among * w;
 
@@ -291,7 +301,7 @@ extern int find_among_b(struct SN_env * z, const struct among * v, int v_size) {
     int j = v_size;
 
     int c = z->c; int lb = z->lb;
-    symbol * q = z->p + c - 1;
+    const symbol * q = z->p + c - 1;
 
     const struct among * w;